Name: SBC CHEVY 350 383 406 NKB-200cc ALUMINUM HEADS 68cc STRAIGHT PLUG NKB-272-PBM
SKU: 27523
Price: 979.00 USD
Availability: InStock

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NKB 200cc/68cc ULTRA HIGH FLOW CYLINDER HEADS WITH PBM COMPETITION VALVES STRAIGHT PLUG, FOR SBC CHEVY 327 350, 355 383, 400, 406 ENGINES.

Setup for hydraulic flat tappet cams.

200cc RUNNERS, 68cc COMBUSTION CHAMBERS.

WE ALSO OFFER THESE HEADS WITH 64cc and 60cc COMBUSTION CHAMBERS.

Important note.

Our eBay user id is: skipwhite, and our eBay store name is whiteperformance1. You may have noticed other sellers using a similar name offering similar products. These other sellers have capitalized on our name as we see it, and many customers searching for us will inadvertently find them, thinking we are one in the same company. There is only one “Skip White.” We are the original premier eBay seller under this name since approximately 2003. We have no other eBay names, nor are we associated with any other company regardless of the similarity in the name or location. Our official company name is Skip White Performance. Please see the article in the lower part of this ad for a more detailed explanation.

THE BEST FLOWING, BEST QUALITY SBC ALUMINUM HEADS ON THE MARKET FOR THE MONEY.

This sale is for one fully assembled set of heads (2 heads).

The springs in these heads are set up to operate with hydraulic flat cams up to .535 lift. For those running hyd. flat tappet cams, see our other listings.

The NKB aluminum heads have 68cc combustion chambers with 200cc runners, 2.02/1.60 stainless valves. These heads are not built by Procomp, and have no association with them in any way.

PART NUMBER # NKB-272-PBM

These heads will accommodate conventional style carburated intakes as well as Vortec (96-up 5.7) style intakes. The heads will not work with pre-Vortec, (87-95) tbi intakes.

Our cylinder heads are made from AC4B alloy and tempered to T6 standards. Details about this alloy are in the lower section of this ad.

These NKB heads have 68cc combustion chambers. The valves in these heads have been upgraded to our Premium PBM race grade valves.

These are custom built NKB-200 aluminum heads with 200cc runners, and 68cc combustion chambers, 2.02/1.60 PBM stainless competition valves, 1.46 diameter dual roller springs. These heads are not built by Procomp, and have no association with them in any way.

The main reason to use a 68cc combustion chamber over a 64cc size is to reduce static compression. For those building a 383 engine setup with flat top pistons for street rod use, this is the perfect combination. The 68cc heads, coupled with the flat top pistons in a 383, will produce right at 10.44:1 compression ratio, assuming your pistons are around .005 in the hole.

If your pistons are at an optimal zero deck ht., then compression ratio would be 10.56:1. with the 68cc heads. These numbers are ideal and reasonably safe for any pump gas 383 street rod. If you were to use the 64cc heads with the same flat top pistons, (.005 in the hole) your compression ratio would be 10.91:1, and if at zero deck ht., 11.05:1. Those numbers are on the high side, and depending on other factors, could put you in the danger zone for detonation.

If you’re calculating your piston to deck ht. at numbers beyond .010 or more, then your overall compression would be lower, but this not the way to build the engine with pistons sitting so low in the block, as the quench/squish zone is very poor to say the least. You should have your block at zero deck ht, (pistons set flush with the deck of the block). There are few if any 383 street rod builds that require compression in the 11:1 zone, especially if you’re running a pair of heads that have 200cc runners and a cam under 580 lift.

Recommended accessories for these heads.

Please see our other listings.

Part	Part Number
Intake gaskets	· Felpro # 1206 · Extra thick: Felpro # 1266
Head gaskets	· Felpro Z-1003-2 · GR-30-PAIR, .030 THICK · GR-40-PAIR, .040 THICK · 5219-PR, multi-layer
Exhaust gaskets	· 5206 oval port
Valve cover gaskets	· 7483 extra thick · 7484
Head bolts	· ARP-134-3601
Head studs	· PCE-279-1001
Spark plugs. See Important Note.	· Champion RC12YC, head range 3 · NGK 4554, heat range 8
Pushrods (length needed may vary; check with pushrod checker)	· HB-BULK-7.250-16 recommended for 274 · HB-BULK-7.900-16 recommended for 272

********************************

Important Note

For those running an HEI distributor, the plug gap should be approx. .040-.045 Those running an MSD 6AL unit should gap the plugs to approx. .035-.040 These values are very controversial and you may experiment as to what runs best in your engine. Widening the gap too much can put a strain on the ignition components. Be sure your plug wires are completely fastened onto the spark plugs.

We certainly know where to draw the line with low end products, and we continue to eliminate parts that we once accepted but that eventually had problems. Sometimes it’s not that a particular product has had a problem that leads to its elimination; something better just comes along. The NKB cylinder heads are that “something better” coming along. Considering the price is only slightly higher than our former line of heads, this has to be the best value in a set of cylinder heads we have ever offered. We now use the NKB heads on all of our 350, 383, and 406 engines. The performance has been outstanding on every combination we have tried them on. In the rare event you have issues with our NKB-200 heads, the problem will be addressed. As of today (2/17/16), we have been selling the NKB heads for around 2.5 years. We have sold approximately 3500 sets, and problems have been near non-existent.

The Felpro 1206 is the intake gasket part number is the most common used with these heads Some intake manifolds will set too low due to their design, and the 1266 extra thick intake gaskets may be required. You may also be able to use the Felpro 1205 intake gasket depending on the style of intake used.

Very Important Note.

If you are using an Edelbrock Performer EPS intake then you will need to use a 1205 intake gasket instead of the 1206. This is due to intake flange not covering the top of the 1206 intake gasket properly. The 1205 is slightly small for the NKB heads, and may need a very slight amount of trimming to avoid any gasket materiel hanging over into the intake runner. We have been through this procedure in our engine room many times for engines using the Performer EPS intake.

These heads are also available in angle plug style, and with steam holes.

Please note: Due to a high volume of sales at this time, these heads may take up to 2-3 business days to complete and ship. Please let us know if you are under a time constraint with this order, and we will do our best to accommodate your request.

A breakdown of the part number.

The NKB stands for “New Kid on the Block”; 200 represents the runner size, 272 designates
the use of 100 long valves, and single springs with a damper setup for hyd.
flat tappet cams. You will also see the heads listed with the number 274. The
274 designates the use of 200 long valves with dual springs with a damper,
setup for hyd. roller cams. We also have the valve train setup for solid roller
cams, and will have the number 583 rather than 272 or 274. The heads listed
with the letter “A” in the part number are angle plug design. We also offer these heads with steam holes for GM 400 blocks. These will have the letters SH (Steam Holes)
in the part number. Be absolutely certain of what you need before
buying. Feel free to call us if you need assistance deciding what you need for
your build.

Heads with PBM at the end of the part number have our premium race quality valves in them, and are only available in the 68cc combustion chamber size. Any of the NKB adds without the letters, “PBM” in the part number will have 64cc combustion chambers. Any of the NKB heads we offer can be setup with PBM valves, but do understand that these valves are what make the 64cc heads into a 68cc chamber size. The PBM competition valves have a concaved face that is much more prominent than regular valves. This increases the combustion chambers size.

See our other listings for these heads with 64cc combustion chambers.

Our NKB-200 heads have been designed
especially for us. After receiving many recommendations from our engine builders,
we came up with the best quality, best flowing heads on the market relative to
cost. The only way you’re going to get a set of heads that flow as well or
better will be to spend at least double the cost or more. We have installed
these heads on all of our 383 and most of our 406 engines for the past 2.5 years. Many of these engines were dynoed on our Superflo dyno. The engines
had every possible combination of cam, intake and carb. The results have been
amazing. These heads are excellent in design and quality. Our choice of
hardware and precision assembly also contribute to the performance and
reliability of the heads.

These heads can be used with outer perimeter or center bolt valve covers.

Flow chart information.

Below is
our flowchart on several different heads. All tests were performed on a
Superflo 1020 bench by our expert head builder. We stand behind the accuracy.
We have noticed many other sellers posting what we consider to be false flow
numbers on the heads they are selling. We find this to be nothing short of
outright fraud. Of course, flow numbers can vary a few points depending on
equipment used and testing methods, but not by 15-25 points. Notice the low
lift flow numbers produced by our new heads. That is as important as the upper
lift numbers, and it’s why these heads produce so much peak power and torque.
We are very impressed with the flow numbers of our new heads.

In the flowchart above, the NKB-200s are superior to the Procomp
heads in flow numbers, and also edge out the Dart SHP heads on the intake side.
The intake numbers are far more important than the exhaust. The overall average
flow numbers on the NKB-200 heads are higher than most any brand of non cnc’d
cast aluminum heads on the market. We guarantee the flow numbers to be
accurate, as well as the horsepower numbers produced by them.

Most importantly, all three of these heads were tested by the same
person, on the same machine, (Superflo bench 1020) using the same testing
method, on the same day. These numbers show the true difference between each
brand, and that’s what counts.

The difference in horsepower and torque generated by these new
heads is monumental compared to the Procomp heads. We offer four different cam
choices with our 383 and 406 engines, and every combination has shown an
increase of up to 50 horsepower and no less than 40 hp when coupled with the
various combos. We assumed the new heads would generate a considerable increase
in power, but to our surprise, they generated even more power than expected.

We tore down the heads that were on our 383 house engine and
checked the guides as this was an area we are most concerned about, and found
zero wear. The seats were also in perfect condition. We tested the spring
pressure to see how much was lost after a brutal 80 or so dyno passes, and saw
approx. 5 lbs of pressure drop on the nose, and even less on the seat, and
this is to be expected.

Many of the dyno passes were run to 6500 rpm as the large cam
needed 6300-6400 rpm to make peak power, and you must run past this to
determine the fall off point. The super sized cam (choice 1) was run on the
heads towards the end. Considering the size of this cam, it was very impressive
to see zero issues with the heads or hardware. We made a good 25 passes with the big
cam trying out different carb sizes, jetting, intake manifolds, timing setting,
and adding the Super Sucker plate last.

Update, 1/15/16

The two paragraphs above were written a couple years ago. We have now sold several thousand sets of the NKB heads. To this date we have had no problems of any kind with them.

ONE YEAR WARRANTY, UNLIMITED MILEAGE.

Here is a rundown on the hardware used in these heads and the assembly process.

Melling High Performance Springs.

Our Melling springs are 1.46 diameter, with an internal damper. Others are using springs that are much smaller in diameter. Smaller diameter springs may be in the correct spring pressure zone, but they usually have a shorter life. Melling springs are made in the UK,(United Kingdom) by a company that is now owned by Melling. Spring failures are near non-existent.

Our valves are high temp stainless steel.

PBM/Erson stainless steel valves, swirl finished one piece undercut, the same valve we have used for years. Our cost on these valves is nearly double the price of some low cost valves on the market. These are made from high grade non-magnetic stainless. We know for a fact that many head builders use the low cost valves. It is very rare we ever encounter a problem with our valves.

Below is a copy of one or more of our invoices from Engine Parts Warehouse showing a recent large order for our PBM valves. We have removed the price and our account number for privacy reasons. This is the best way we can prove to our customers that the valves we use in our cylinder heads are genuine PBM products.

COMP CAMS “POSITIVE STOP” VITON VALVE STEM SEALS. # 529-16

Comp 10 degree machined valve locks.

We use only Comp Super 10 degree machined locks. Our head builder noticed the low grade locks on the market fit more loosely than he felt they should, not to mention the possibility that they were made of inferior metal. He envisioned the engine being much more prone to dropping a valve at high rpm. Using these locks, we have yet to have an engine drop a valve due to a valve lock failure.

Comp Cams retainers # 75740-16 and Comp Cams ID locators Part number: 4771-16

Our Comp Cams retainers # 75740-16 and Comp ID locators # VTH-4771-16 are made from 4130 chromoly steel. These retainers have a perfect fit with the Comp valve locks. We have used these on all of our engines for many years, and have had zero failures.

Assembly Procedure

We hone all of the bronze valve guides with a ball berry flex hone to establish not only perfect clearance, but also a semi cross hatch finish for oil retention. We finish off with a natural bristle brush. The heads are then placed in our parts washer and cleaned with high pressure hot water, then pressure dried. Before installing the valves, we apply a heavy coat of engine assembly lube to the valve stems. The coating on the valve stems is essential to protect the bronze guides from gaulding on initial startup.

Our next step is to set the spring pressure to a predetermined pressure using a spring height checking device, most suitable for street rod use. The springs we are using allow for a near perfect seat to nose ratio. Be warned that some sellers of aftermarket heads may not be checking the installed height when assembling the heads, and may not be setting them up to the correct pressures. We have a full scale machine shop with several very knowledgeable engine builders that know and fully understand how to properly assemble a set of heads. Combine the possibility of poor assembly methods with incorrect or low grade hardware, and it is easy to see how failures can result.

We purchase most of our valve train hardware in bulk for our engine program. Below is a copy of one of our invoices from Comp Cams showing several of our rather large purchases of valve train hardware. We have removed the price and our account number for privacy reasons. This is the best way we can prove to our customers that the valve train products we use and sell are genuine Comp Cams products.

IMPORTANT NOTE CONCERNING ROCKER ARM STUDS.

If you have been a regular shopper with us, you will have noticed we do offer some knock-off products that are made off-shore. We do also sell many products made in the USA. We have always been very particular as to the quality and workmanship of such products, while considering the cost. We scrutinize our products very carefully and refuse to sell products that simply don’t meet our standards. We have now eliminated another of the low cost knock-off products from our line. The low cost imported rocker arm studs have shown numerous problems unlike those in the past. We have looked at several others on the market, and still find many issues with them that are not acceptable.

Many of the studs had run-out in the shaft of up to an eighth of an inch. This caused major problems with rocker alignment, and depending where the position was when the stud tightened up, would determine the direction of the rocker misalignment. If the warped stud was facing toward or opposite the valve, then the roller tip would would not be centered to the valve tip. This would then create a loss of lift and cause increased wear on the valve tip.

If the warped stud tightened up in a side to side position, then this would allow the rocker tip to be cocked on the valve tip. This would then side load the valve tip with undue pressure, creating a serious wear problem on the side of the valve tip and create excessive wear on the valve guides in the heads. This also side loaded the rocker trunnion and front roller, creating an excessive wear issue in the roller rockers.

We also found a difference in the tread pitch and depth compared to the ARP studs. The rocker studs in an engine are under a tremendous upwards pull and improper thread design may cause the studs to pull out of the head. The ARP studs screw into the heads with a very precise fit and feel.

After thoroughly comparing the ARP studs and several off shore models, I am convinced that we will never offer the off shore studs again, regardless of the price difference. They were never as bad in the past as what we’re seeing now. This run-out was most likely caused by improper heat treating methods.

We are aware of only one other rocker arm stud besides ARP on the market of decent quality, and that’s from the GM Performance division, and it’s fair to say they are most likely supplied to GM by ARP under private label.

We have rejected many products that are outright junk and would cause serious issues in your engine only to see other sellers offering those same exact products. It’s all about learning where to draw the line.

Studs and guide plates are NOT included. Other sellers may include these items but rest assured, they are usually not suitable for these heads. We use nothing but the Dart adjustable guide plates and ARP rocker studs when we build an engine using these heads, as they allow for perfect alignment of your rockers. See our other listings for a full selection of accessories.

See our other listings for valve train related items that you may need for your project. The part number for the correct studs and our Dart guide plates to be used with these heads is 38-GP for those running 3/8’s size roller rockers, and for those with 7/16’s roller rockers the part number is 716-GP These kits are available in our other listings.

We are glad to offer many great low cost items, as well as the high end products, but will always give careful consideration to quality, functionality, and overall value.

IMPORTANT NOTE, MUST READ!

We have noticed several sellers offering these heads with a one size fits all valve springs for dual use on hydraulic flat tappet and hydraulic roller cams. We are sure this is not the proper way to setup the heads.

If they have this one size fits all setup somewhere in the middle spring pressure values of what is required for a hyd. flat tappet and a hyd roller cam, then it would be too much for the hydr. flat tappet cam, and create a wear issue. Putting too much pressure on flat tappet cams is a sure way to kill the cam. If these middle of the road springs were used on a hyd. roller cam, then the spring pressure would be too low. Valve float and its damaging effects, along with a loss of performance, are sure to occur.

We use the correct spring for your setup and it is never the same on a hyd. flat tappet as it would be on a hyd. roller cam. As mentioned above, the spring requirements between a roller cam and flat tappet cam are dramatically different. Even the odd ball solid flat tappet cam has its own unique setup depending on the lift. The one size fits all hardware claims also to work on these cams. We know of several sellers offering this insane setup to unsuspecting buyers, and it’s not the proper way to set up a set of heads. We would not even consider using a spring setup like this, and believe me, the simplicity of it is appealing.

Our cylinder heads are made from AC4B alloy and tempered to T6 standards. You may have heard the alloys 355 and 356 being used on many heads. The alloy used on our heads is similar but slightly different. The AC4B alloy is commonly used by automakers in Europe and Japan. Take notice of the Rm value. This value indicates the tensile strength of an alloy. As you can see, it’s higher than all the other common alloys in this chart. It’s no surprise as to why we have never experienced a failure of any kind with these heads. Zero failures in the casting, zero failures in the seats and guides. We have sold over 5000 pair of these heads over the past four years.

List of Standard Alloy Characteristics

Alloy +B4: H16		AC4B	AC4C	AC4CH	AC4D	AC7A
Mechanical properties	Rm (MPa)	345	285	260	320	245
	R0.2 (MPa)	250	225	157	240	105
	A (%)	1.6	7.3	16.8	4.1	5.3
Temper		T6	T6	T6	T6	F
Features		High strength, small elongation Castability: good, for general purposes	Castability: good Pressure resistance, corrosion resistance: good	Castability: good Mechanical properties: good	Castability: good Pressure resistance: good	Corrosion resistance: excellent, anode oxidized Castability: not good
Examples of applied parts		Crank cases, cylinder heads, and manifolds	Hydraulic parts, transmission cases, aircraft parts, lighting components, etc.	Wheels, engine parts, hydraulic parts, aircraft parts, etc.	Cylinder heads, crank cases, fuel pump bodies, etc.	Parts for overhead contact lines, parts for ships, business machines, and lighting components for aircraft

The results produced by these heads will vary greatly depending on the type of setup you are running. The engine combos we have dynoed are what most people use for cam and intake selection, and the results are listed below. The engines dynoed were many 383’s, and several 406 cid engines in the 10:1 to 11.2:1 compression range. All ran on pump gas. Our Stage 2.0 383 engine ad has a selection of four different cams. I have copied this info from that ad. This will give you an idea about the capabilities of these heads with combinations of cam, intake, rockers, and carb. This may also help you select the proper cam for your build.

As mentioned, below is just an excerpt from our Stage 2.0 engine ad. We also built and dynoed a 350 engine recently with the new NKB-200 heads for a customer, and will have the actual dyno results in this ad soon. The cams mentioned below are all hyd. roller cams. If you’re using a lower lift than those listed below, then it would be fair to say the hp will drop, but not by much, providing your lift and duration are somewhat close to any of the cams mentioned below. This will give you an idea of what kind of power to expect with these heads, and it can certainly help you choose a cam and intake.

Please do understand that a cam is not included with the heads. This is just a guide to show what you may expect with a given combination when building a 383 engine using the NKB heads.

photo 384eb881-7875-44b7-975a-0b7027c8c150_1.jpg

Cam Choice #1

Special Grind # 33161

PART NUMBER: 08-000-8-11323

520/540 lift

236/242 duration

110 lobe sep.

Comp Cams SBC Xtreme Energy Step Nose Hydraulic Roller Camshafts.

This cam choice, coupled with our single plane intake and our -7.5cc

forged pistons with 1.5 rockers, will produce right at 503 horsepower at approx. 5,900 RPM. We recommend the dual plane intake for better drivability, and throttle response. The dual plane intake will move the torque down lower in the rpm range. The single plane intake would allow the engine to make its peak advertised horsepower at the peak rpm, but these type intakes move the torque band higher up in the rpm range. Expect a slight loss of top end power with the dual plane intake, but low speed drivability and cruising are greatly improved. If you car is in the lighter weight range and has a decent final gear, (3.55-3.73 or numerically higher), then you may select this build with our flat top pistons and 6 inch rods at no additional cost. The compression range is a bit on the high side, but considering the flat top pistons allow much better combustion, detonation is really not a problem. An octane boost additive would be recommended.

The single plane intake is not recommended for use in vehicles weighing over 3,800 lbs unless your vehicle is set up with a somewhat deep final gear, (3.55-3.73 ratio). Our cam timing components were left in the straight up position. Ignition timing was set at 34 degrees total and 93 octane fuel was used. During very hot weather, total timing should be set at 31-32 degrees. A final gear of approx. 3.73 or numerically higher, and a stall of approx. 2,500 would be the bare minimum. Preferably a stall speed of approx. 3,000 to 3,200 would be highly recommended, especially if you have chosen this setup with a single plane intake.

Below are our dyno results on one of our 383 engines with this cam choice with a single plane intake and the 1.5 rockers. Results will vary depending on intake and rocker choice. The horse power numbers will usually improve anywhere from 5-10 HP more than what the dyno results show after the rings have fully seated.

Official Dyno report on our 383 engine with this cam choice, a single plane intake with 1.5 rockers, a Brawler carburetor, and an HEI distributor.

photo 37b38ead-a57e-462e-ab02-a25eaef350ae.jpg

Important note.

If you choose cam choice 1 with the single plane intake combination, it is highly recommended that you upgrade the ignition system to an MSD Pro Billet distributor and CDI unit. You may also want to upgrade the carburetor to the Brawler dual pumper series. The acceleration and overall performance is greatly enhanced with the Brawler mechanical secondary carburetor. These important upgrades are essential for improved tuning, idling and overall performance. If you do decide to use the MSD Pro Billet distributor, we suggest you use the black timing degree bushing to increase the initial timing and possibly the lighter springs to control how soon the mechanical advance comes in. You may even “lock-out” the distributor, depending on your car’s overall setup. The CDI unit will make a huge improvement in how the engine runs at idle and low speed cruising, as well as high rpm operation.

Cam choice #2

Special Grind # 33151

PART NUMBER: 08-000-8-11480

510/525 lift

230/238 duration

111 lobe sep.

Comp Cams SBC Step Nose Xtreme Energy Hydraulic Roller Camshafts.

This cam choice is the perfect all around setup for those wanting a decent bottom and mid range while still generating excellent power at the top. Horsepower rating would drop off by approximately 25 with this cam when using the single plane intake and 1.6 rockers. This setup will generate its peak power at approx. 5600 RPM and this can vary depending on rocker and intake choice. Vacuum is increased with this cam compared to cam choice 1.

If your car is in the medium weight range or up to approx. 4,000 lbs, and you want slightly better streetability, then this is a very good cam choice. You still want to keep the final gear ratio at 3.55 or numerically higher. You may choose 1.5 or 1.6 rockers with this cam, but we recommend the 1.5 rockers if you would like to further improve low end response. A stall converter in the 2500 rpm or higher range would be suitable for this setup.

This cam should be paired up with the dual plane Crosswind intake for better drivability. The single plane Hurricane can be used, but the dual plane will have much better bottom end and mid range response. You can also expect a longer valve train life with this cam compared to the larger cam choice. This cam will also have a lopey idle, but not as radical as the larger cam above.

Official Dyno report on our 383 engine with this cam choice, a single plane intake with 1.6 rockers and a Brawler 750 carb.

Official Dyno report on our 383 engine with this cam choice, a single plane intake with 1.5 rockers and a Sniper EFI system.

Cam choice #3

PART NUMBER: 08-000-8-13436

498/502 lift

220/226 duration

111 lobe sep.

Comp Cams SBC Step Nose Xtreme Energy Hydraulic Roller Camshafts.

This cam choice has a lower lift and duration than the others offered above, and is highly recommended for use in heavy cars or full size sport trucks. The low end response and mid-range power with this cam is very good. Horsepower rating would be approx. between 405-420 depending on intake and rocker choice.

The rule of thumb for cam size: the smaller the cam in a given application, the better will be the low end response. One more benefit to the smaller cam is the reduced requirements for lower gearing and higher RPM stall converters. A final gear ratio of 3.30 would be acceptable with this cam.

This would be the only cam choice for running an overdrive transmission such as the 700R4 cruising at around 2000 RPM in overdrive. A stock stall converter may be used with this cam, but for improved acceleration, a 2000-2250 stall is recommended, especially in heavy vehicles with a tall final gear. If you are running an overdrive transmission, then choose this cam with the 1.5 ratio rockers, and the Edelbrock EPS intake.

Valve train life is greatly extended with this cam as compared to the others, and drivability is at its best. Low and mid throttle response is very strong. This cam choice will also produce the greatest amount of vacuum at idle compared to those listed above. You may run power brakes with this cam. This cam is best paired up with our Edelbrock EPS intake. This particular intake is offered at no extra cost. The EPS intake actually has amazing off idle power compared to any of the larger runner dual plane intakes. This intake is the most practical intake to select when you use this cam. Fuel mileage would be at its best with this cam and the EPS intake. We also run a lower compression piston with this combination, making the engine less prone to detonation.

Official dyno results with this cam, 1.5 rockers, dual plane EPS intake, SL-600 carburetor, NKB heads, and an HEI distributor. Notice the rpm range where we started this dyno run with this cam. We are unable to start a run at this low of an rpm with any of the larger cams used in a 383 engine. The torque numbers this cam produces in the off idle range would be far greater with this cam and intake combo than with any of the larger cam selections.

Notice the torque curve on the graph below. This combination is all about huge low end torque. We started the pull on this at 3600 rpm, and that can’t be done on any of the cams above. The torque in the low rpm range with this cam is very impressive.

THE CAMS LISTED WILL COVER MOST NEEDS FOR ANY STREET ROD OR SPORT TRUCK.

An excerpt from our engine ad about our new dyno.

As of 9/15/2013 we completed installation of our brand new Super Flow 902S dyno. In the past, we outsourced our dyno work. We were unable to do the research and development we truly wanted, and this prompted us to make the $105,000 investment. It’s been one of the best investments we have ever made. Every aspect of our engines can now be monitored, calibrated, and tuned. Best of all, we can now see what combos generate the best power, with consideration to drivability.

Update, as of 3/1/16 we have installed our second new Superflo dyno. After the new dyno was setup, Superflo sent out two factory techs to calibrate it, and install the software. We made a comparison between the two dynos with one of our engines, and found them to be within one horsepower of each other.

VERY IMPORTANT-Head bolt recommendation.

The NKB and our AFR sbc heads require the use of ARP 134-3601 Head bolts only. They are far superior to virtually any of the other common head bolts on the market. They have specially designed extra thick head bolt washers, and extended reach head bolts. Using stock length head bolts will not allow the use of the extra thick special washers required, as the OE bolts have a limited amount of thread on them. Not using the ARP head bolts may cause serious damage due to the fact they will gouge into the aluminum surface of the head and not only can this cause a possible break-through into the runner section of the head, especially in the center cylinders, the torque readings are often very inaccurate due to the drag created as the bolt head gouges into the aluminum surface. There are many other critical reasons not to use stock or most any of the other off brand head bolts with these heads, too many to mention, but rest assured the problems associated with can be very damaging. We will soon be doing to video to demonstrate the reasons and importance of using the ARP head bolts recommended in this ad. We do offer the correct AFR head bolts in our other listings.

Guide plate recommendation.

We strongly recommend the use of the AFR two pc. adjustable jig saw puzzle style guide plates with these heads The two pc. adj. guide plates will allow better rocker tip alignment due to the fact they are highly adjustable. We use them on every set of heads we install on our engines. The two pc. adjustable guide plates allow a great amount of correction for proper alignment of the roller tip on the valve tip. By having proper rocker tip alignment, you are distributing the pressure on the valve tip evenly. This not only reduces uneven valve tip wear, but also prevents undue stress on the valve guides in the heads. See our other listings for the AFR two pc. adjustable guide plates.

Pushrod recommendation.

We recommend not using stock GM pushrods with these
heads. The spring pressures on aftermarket heads are somewhat higher than on OE
heads. Combine this with the larger lift and duration cams often used, and
stock pushrods may flex or permanently bend. The stock pushrods are usually
made from a mild 1810 steel that has been heat treated. Under high rpm they
will usually flex and cause a loss of lift resulting in a power loss. The
engine will usually run erratically when pushrods are flexing. The Spintron
valve train dyno proves that inadequate pushrods will flex to a great degree as
engine rpm increases.

Some GM pushrods have a welded ball on them, and they stand a
greater chance of breaking off with the use of larger than stock
cams, and increased spring pressure. We offer pushrods made from 4310 chromoly with an .080 wall thickness. They are superior to any stock pushrod. Our prices
on them are the best you will find.

The size that you will
most likely need with the NKB heads will be 7.250. This
size has worked well for us when using the Comp high energy or Scorpion brand rockers. There
are many low cost pushrods on the market in the $29-$39 range. These low
cost pushrods are totally unsuitable for use with these heads for the many
reasons mentioned above, and they are not guide plate compatible. They usually
have a wall thickness of only .065. These pushrods will cause problems when
used on a high performance setup. There are many factors that can
determine pushrod length requirements. The 7.250 length
is the most applicable. Should you purchase a set of pushrods from us and find
that the length is not suitable, you may return them, and we will send out the
size you request.

Stud Girdle recommendation.

If you are running full roller rockers, we recommend tall valve covers, and this can cause the oil that is pumped up into the top of the heads to not be deflected back down onto the valve springs, valve tips and roller rockers. The lack of oil on these parts can lead to not only a lack of lubrication but also to a lack of cooling on these parts. Heat transfers up the valve stem from the combustion chamber. This heat is very high in temp, and may cause serious damage to the valve guides, springs and roller rockers.

The cure for this would be to install a low cost set of stud girdles. Stud girdles increase stability to the rockers’ studs, eliminating flex that is may be present to some degree when running cams several sizes over stock, not to mention increased spring pressures over stock. Stud flex robs your engine of power and smooth operation in the upper rpm ranges. As mentioned above, another very important aspect of using stud girdles is that they deflect oil directly back onto the valve springs, valve tips and roller rockers. On a stock engine this is not an issue due to the fact that stock valve covers are very close to the top of the rocker arms.

If you have ever removed the valve covers on an engine while it is running you would notice that the oil sprays up out of the back side of the rockers and goes in all directions. The most important reason that oil is brought up into the top of the engine is for lubrication and just as importantly, to cool the valve train components. The oil temp does have a great cooling effect, as its temp is only around 215 deg. and the heat that is transferring up into the valves and springs is far greater than this. If oil were not flushed onto these parts, lack of lubrication would be just one problem. Valve guides and stems that are heated up to high temps, and also lack the proper lubrication may experience excessive wear. We suspect that these parts may be stressed due to the oil not being redirected back onto them, and stud girdles would positively protect these parts to a great degree.

We now use them on every engine we build regardless of the degree of cam and spring pressure. Those running cams that are above 460 lift should use stud girdles, since this is about the level that stud flex may come in, especially when running the smaller 3/8’s rocker studs. Excessive valve guide wear along with other valve train components can be very expensive to repair.

NKB-200 64cc 200cc RUNNER SIZE STRAIGHT PLUG FOR SBC CHEVY ENGINES

Intake Valve Dia: 2.02″

Intake Port volume: 200cc

Intake Port Dim: 2.2″ x 1.2″

Int Port Location: Stock

Intake Gasket: Felpro# 1206 fits perfectly with most intakes. Should your intake drop too low, then the 1266 gaskets will correct this problem. Our line of intakes have worked very well with the Felpro 1206 intake gaskets.

Head Gasket: Felpro# 1003 or our line of GR-30 and GR-40 heads gaskets.

Exh Valve Dia.: 1.600″

Exh Port volume: 70cc

Exhaust Port Dim: 1.356″ x 1.420″ w

Exh Port Location: Stock location & bolt pattern

Exhaust Gasket: Depends on what type exhaust you’re using. Best to try and match up the gasket to your header or manifold

Flow, Intake: See chart above.

Flow, Exhaust: See chart above.

Head Bolts: We strongly recommend ARP # 134-3601 head bolts. Do not use oe, (stock) head bolts.

Head Studs: PC-2451-Studs (12pt) or ARP brand.

Manifold: Most any. Our line of intakes fit very well on the NKB heads.

Milling: Min. Down to 58.5cc or 64.5 = .060 See info in this listing for details on this.

Pistons: Most 23°aftermarket pistons.

Push Rod length: When running a hyd. flat tappet cams use 7.900 length. See our other listings for the best deal on premium pushrods.

Push rod Guide Plate: We strongly recommend Dart flat guide plates. See our other listings for these.

Retainers/Locks: Chromoly Steel Retainers, with 10° Comp brand machined locks are used on all of our heads.

Spark Plug: Straight, .750″ reach, gasket, Champion RC12YC or NGK 4554 premium plugs.

Spring Pockets: 1.550″ OD (.030″ deeper max)

Springs: Melling 1.46 outer diameter. Single with a damper.

Valve Length: 5.015″ (+.100″) for hyd. flat tappet cams or + .200 for hyd. roller cams

Valve Stem Dia: .3415″ – 11/32″

Valve Train: STD SBC 3/8″ or 7/16″ stud mount

Valve Guides: 1/2″ OD Int = Mag-bronze Exh = Phos-bronze (.002″ press)

Valve Guide length: 1.950″

Valve Guide clearance: .0014″ – .002″ (with our .3415 dia. valve stem)

Valve Guide Spacing: 1.890″ moved .030″from stock

Valve Seats: Hardened Ductile Iron, .006″ press

Valve Seat dim. Standard

Valve Seat angles: Int = 32° – 45° – 60° – 70° Exh = 37° – 45° – radius

Stud Girdle: Use any standard girdle. Our Gold Series Stud Girdles work very well on these heads.

Torque: Head Bolts = 65 ft/lb

Rocker Studs = 55 ft/lb

Manifold = 30 ft/lb

Block Use: Any SBC Iron or Aluminum

Weight: 58-60 lbs fully assembled pair.

Important installation notice.

As with any new heads, you must do a mock setup with the heads before bolting them on. This is done by setting the heads on the engine and using two bolts to hold the heads in place. This will allow you to check your pushrod clearance, and verify that your rocker studs are all in line. In rare instances, if your pushrods are touching any surface of the heads, you will have to dremel these spots for clearance. We have seen this situation with many aftermarket heads, including Dart. There are areas of the casting that are very close to interfering with pushrods, and it will only take seconds to correct, but you certainly don’t want to have completely bolted the heads on and find this out. We received a large order of Dart heads that had an interference issue with the pushrods, and as mentioned, it only takes seconds to correct this with a dremel tool, but not if you have secured all 34 head bolts. You cannot correct such issues with the heads on the engine due to the risk of contamination of the rest of the engine. See our other listings for items you may need to complete your engine build.

IMPORTANT NOTE CONCERNING ROCKER ARM STUDS.

The most serious issues included the fact that many of the studs had run-out in the shaft up to 150 thous. This caused major problems with rocker alignment, and depending where the position was when the stud tightened, would determine the direction of the misalignment. If the stud position was facing the valve, then the roller tip would not run off to the side of the rocker but it would cause the roller tip not to be centered on the valve. This would then create a loss of lift.

However, another issue concerned us most of all. The warped stud shaft of some of these studs would allow the rocker tip to be cocked on the valve tip depending on the position it was tightened at. This would then side load the valve tip with undue pressure creating a serious wear problem on the valve tip and valve guides in the heads. This also side loaded the rocker trunion and front roller creating an excessive wear issue in the roller rockers.

We also found the difference in the tread pitch and depth to be dramatic compared to the ARP studs. The rocker studs in an engine are under a tremendous upwards pull and improper thread design may cause the studs to pull out of the head. The ARP studs screw into the heads with a very precise fit and feel.

After thoroughly comparing the ARP studs and several off shore models, I am convinced that we will never offer them again regardless of the price difference. They were never as bad in the past as to what we’re seeing now. This run-out was most likely caused by improper heat treating methods.

We are glad to offer many of the low cost items that are off-shore, but will always give careful consideration to quality, functionality, and overall value. We will not sell imported after-market rocker studs going forward.

You will notice that we offer many US-made products, but we may not offer those same items in off-shore lines. It certainly is not because we don’t have access to the low cost off-shore product, but because of quality issues that we have discovered. We have rejected many products that are outright junk and would cause serious issues in your engine only to see other sellers offering those same exact products. It’s all about learning where to draw the line. We are aware of only one other rocker arm stud besides ARP on the market of decent quality, and that’s from the GM Performance division, and it’s fair to say they are most likely supplied to GM by ARP under private label.

Stud Girdle recommendation.

Skip White

A final note…Skip White Performance…About Us

I’m sure many of you have noticed there are 2 high performance engine builders in Kingsport, TN with similar names, leading to a great amount of confusion.

We are Skip White Performance, NOT White Performance and Machine.

Due to the name similarity, many customers looking for us online inadvertently find them, thinking we are the same company. Definitely not…there is no connection between the two companies. We don’t have a problem with free enterprise (competition). However, when the competition builds their foundation on such things as a name similarity and their supposedly long history of being in business, then we think it’s about time we set the record straight.

We have owned White Performance since 2003, with the exception of the machine shop, which was owned by Fred White at the time. He continued to operate the machine shop and build engines for us while we continued selling online under the eBay user ID of skipwhite and the eBay store name of whiteperformance1.

Due to their limited production capability and many disagreements about the engine and head building process as well as workmanship, we opted to open a full scale machine shop of our own a few years later. Fred White began competing against us even though our contract had a non-compete clause in it.

As our business grew, we opened a second, much larger warehouse and machine shop around 2011, located on Brookside Ln. in Kingsport TN. By putting heart and soul in this company, we have become the number one street rod engine builder in the nation.

Fred sold his shop to an investor in 2016 and the new owners continue to reap the benefits from this confusion between the two shops. This investor lacked any knowledge of this industry. They continue to use the White Performance & Machine name. Contrary to what is posted on their website, Fred White is no longer associated with the company in any way. Their main spiel in advertising is, “In business since 1979,” when in fact, we purchased the White Performance company in 2003, with the exception of the machine shop.

All in all, we have been in this business going on 17+ years. Skip White’s passion has been owning and building street rods for 47 years on a personal level. The knowledge he has gained over time has allowed him to venture into this business and succeed to a very high level.

The great pretenders continue capitalizing on our success due to the name similarity, but have been degrading our reputation. We have been getting calls nearly on a daily basis from people that now realize there are two shops in this town with very similar names. Customers complain of serious problems in getting their orders in a timely manner from them. They think they purchased their cylinder heads from us. Due to the confusion, there is an increasing amount of negative feedback that is affecting our name within the street rod community, when in fact we have a near perfect reputation in this industry. We have an “A+” rating with the Better Business Bureau and we have maintained the A+ rating for many years.

FAST FORWARD TO PRESENT DAY…We have become the largest street rod engine builder in the nation. Our engines, rotating assemblies, and cylinder heads are built to very high standards and shipped to our customers in a timely manner. We are a premier seller on eBay with a positive feedback score of well over 206,000 and growing, as compared to our competitor’s score of approximately 24,000.

Our engines are custom-built to our customers’ specifications and are shipped in approx. 2-5 weeks, perhaps sooner, depending on the season. Our rotating assemblies usually ship out in about one week or less, and our heads ship in about a week or less.

- We are not responsible for collateral damage caused by the use of this product.

RETURN POLICY

Should a problem occur, please contact us. If a return is necessary, please contact us for an RGA number and return authorization. The RGA number must be included on the return label. If an item is returned without an RGA number, it will not be processed. A full description of what the problem is needs to be included with any returned product with your contact info, and proof of purchase. Even though you may have explained the problem to us, and been granted permission to return the product, we must have a written explanation and a contact number included with the product. It is also recommended that you include the name of the person from our company that you have been in contact with. You must send the item back to us in a trackable manner (USPS Priority Mail, FedEx, etc.) and keep the tracking info of the returned product. Please give ample time for returns to be processed. Following these guidelines will make the return process work as it should.

PAYMENT AND SHIPPING DETAILS.

We offer great discounts on shipping. You only pay the full shipping fee on the highest shipping cost of your items, and HALF PRICE shipping on all additional items. Few offer discounts on shipping such as this. Our checkout system will automatically calculate your shipping discount at the time of final payment, providing you consolidate your payment.

You may receive a verification and tracking number shortly after purchase, but this does not necessarily mean that your product has shipped. It would be fair to say that 98% of products will be going out the day the shipping label is issued. On occasion, the product may not ship out until the next day after the label has been issued. Most products purchased late in the day will not be shipped until the next day.

If you checkout and start over, the auto calculator will not recognize the multiple purchases, and there will be no shipping discount.

UPS is our primary shipper. We are unable to ship to APO/FPO addresses or PO Boxes. Help us ship your order promptly by including your physical address at checkout. Below is a map representing the estimated delivery time to get to you from our location.

Delivery times may vary, especially during peak periods.

UPS delivers Monday – Friday, except for national holidays. If a package leaves here on a Thursday, and you are in a 2 day delivery zone, your package will deliver to you on Monday. Expedited shipping is available upon request for an additional fee. Please contact us for rates. The estimated shipping time is usually as the map shows, but many factors can delay this.

Alaska is in a 3-day ship zone, Hawaii is in a 6-day ship zone, and Puerto Rico is in a 4-day ship zone. Additional fees will apply to shipments to these areas, as noted below.

The shipping quoted in this ad is only for the 48 continental United States. If shipping to anywhere else, please contact us. The half price shipping on all additional items also only applies to items that are being shipped in the 48 continental United States.

Brand	NEW KID ON THE BLOCK 200
Manufacturer Part Number	NKB-68cc-272-ST
Finish	ALUMINUM

Your Engine Experts

(423) 722-5152

(423) 722-5152

SBC CHEVY 350 383 406 NKB-200cc ALUMINUM HEADS 68cc STRAIGHT PLUG NKB-272-PBM

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Skip White Performance

Tri-Cities Website Design.com

(423) 722-5152

SBC CHEVY 350 383 406 NKB-200cc ALUMINUM HEADS 68cc STRAIGHT PLUG NKB-272-PBM

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Skip White Performance