BBC CHEVY 496-572 AFR ENFORCER 335cc ALUMINUM HEADS ASSEMBLED 272-BBC-ENFORCER

AFR ENFORCER 335 FULLY ASSEMBLED BBC HEADS.

. SETUP FOR USE WITH HYDRAULIC FLAT TAPPET CAMS UP TO 580 LIFT. SEE OUR OTHER LISTINGS FOR THESE HEADS SETUP FOR USE WITH HYD. ROLLER AND SOLID ROLLER CAMS. 123cc COMBUSTION CHAMBERS 335cc runners. This sale is for a set of heads (2 heads). GENUINE ARP ROCKER STUDS, AND COMP ADJUSTABLE GUIDE PLATES INCLUDED.     ARP ROCKER STUDS INCLUDED. AND COMP ADJUSTABLE GUIDE PLATES. GENUINE ARP 7/16 ROCKER STUDS. # 100-7101  CHECK OUT OUR NEWEST DYNO RESULTS POSTED BELOW USING THESE HEADS ON OUR BBC 572 PRO-STREET ENGINE. 830hp ON PUMP GAS. IT’S AMAZING THAT THESE HEADS ARE CAPABLE OF MOVING THAT MUCH FUEL AND AIR TO PRODUCE THIS POWER IN A PUMP GAS STREET ROD ENGINE. THAT IS OUR BEST HP NUMBERS ON A PUMP GAS SETUP TO DATE, AND WHO KNOWS HOW MUCH MORE THEY ARE CAPABLE OF. WE HAVE ACHEIVED APPROX. 875 ON A RACE FUEL SETUP, (12 TO 1 COMP. RATIO) WITH DOMINATOR CARB. I WOULD SAY THAT’S GOTTA BE THEIR LIMIT, BUT WE DON’T REALLY KNOW. CONSIDERING THESE HEADS ONLY HAVE A RUNNER SIZE OF 335cc’s THEY HAVE BEEN THE BEST HEADS FOR THE MONEY WE HAVE EVER OFFERED. THE DYNO REPORT WILL BE THE VERY LAST ONE IN THE LIST OF DYNO REPORTS BELOW. WE WERE ALSO VERY HAPPY WITH THE WEIAND TRACK WARRIOR INTAKE USED ON THIS TEST. 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. We also have these heads setup for use with hyd. and solid roller cams. See our other listings. Important note.  These heads are not suitable on 396 or 402 engines that have the less then 4.250″ bore size. With the larger 2.250″ intake valve on these AFR heads, it can interfere with the cylinder wall. These heads are well suited on 4.280″ and larger bore BBC engines. The recommended compression would be from 9.8:1 to 10.5:1 with pump gas, taking advantage of the aluminum castings. The AFR Enforcer 335 bbc rectangular port heads are perfect for 454, 496, 540 and 572 street/strip engines. These are what we now use on our 505, 555 and 572 bbc engines. They produced 762 hp with our Comp 575 lift hyd. roller cam and single plane intake manifold on a 572 pump gas build. We’re estimating approximately 650 hp in a 496 build with the same mid size cam. None of the low cost bbc heads on the market have this performance that we know of. Fully built with premium hardware, ready to install. 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. We certainly know where to draw the line with low end products, and we continue to eliminate parts that we once accepted but for various reasons no longer carry. Sometimes it’s not that a particular product has had a problem that leads to its elimination; something better just comes along. The AFR 335 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. The performance has been outstanding on every combination we have tried them on. In the rare event you have issues with these heads, the problem will be addressed. So far problems have been non-existent.  AFR 335cc ENFORCER ALUMINUM HEADS. PICTURED BELOW IS A SET OUR AFR ENFORCER HEADS WE INSTALLED ON AN ENGINE IN THE BUILD PROCESS. Assembled by us with premium PBM competition grade valves, Melling springs, Comp retainers, Comp Viton valve seals, Comp spring ID locators, Comp 10 degree locks. Notice the multi angle valve seat cut. These heads are designed to very high standards. More pictures below of some the details on our new AFR Enforcer heads. Pictured below is a heads up shot of the front. The AFR logos on the front of the heads really stands out much better in person. The indoor lighting and camera flash created a good bit of glare.  All of our bbc engines sold as of 2/26/22 will have the AFR 335 Enforcer heads on them. They will display the AFR engraved logo in the front of heads as seen in the picture below of an engine we were in the process of building. Many customers in the past have upgraded to the AFR heads so we have decided to include them on all of our BBC engine builds. The quality and detailed machine work is outstanding as compared to any of the low cost heads on the market. Below are our actual flow numbers for our new line of AFR Enforcer bbc heads. These numbers are true and accurate. The testing methods we use are considered to be on the conservative side. Some choose to show flow charts for their heads that have been done in a way that shows numbers that are misleading in our opinion. We now use the AFR Enforcer heads on most all of our bbc engines builds all the way up to our street rod 632 engine. The horse power numbers they produce are exceptional as compared to most heads of this size.  The correct intake gaskets to use with these heads can vary greatly depending on what intake your using and whether your block has been decked excessively. Below are several common intakes we use in our engine room. There are other intakes on the market, but we have not used them, so we are unable to say exactly what they might use. As mentioned this can also vary on how much the block has been decked. If it has been decked a multiple times or to a great amount then it’s fair to say the thinner felpro 1275 gasket is the correct choice versus the 1275-5 thick version. If you are using the Edelbrock RPM Airgap, then it will always be the felpro 1274.  Profiler single plane, felpro 1275 Speedmaster/Procomp/Pro Products Hurricane single plane, felpro 1275-5  Edelbrock RPM Airgap dual plane, felpro 1274  Weiand Track Warrior single plane, felpro 1275   As for head gaskets, our experience has been that the felpro 1017’s are perfect for those using a 454 or Dart block for builds up to 505 cubic inch. For those using a later model 502 GM block these gaskets are NOT the correct ones to use. Were not sure exactly what the correct head gasket to use on the GM 502 blocks would be. When using a Dart Big M block or World/Merlin block to build engines 540 cubic inch or bigger the correct felpro head gaskets would be the # 1057 or 1067. One other important factor is that the head gaskets must have an opening of at least 4.560″ for the 496 cid builds. Were aware that these engines only have a bore diameter of 4.310″ but the AFR heads have a larger opening around the combustion chamber and require a head gasket with a large opening. This is standard with all aftermarket high performance aluminum heads. There are plenty of other brands of head gaskets on the market, and the felpro numbers mentioned can be crossed over to them.  In the lower section of this ad, you will find valuable information on how these heads perform when used with various engine sizes and cam combinations in street rod form. Please read the complete ad before purchasing.  Fully assembled with premium PBM competition grade valves, Melling springs, Comp retainers, Comp viton valve seals, Comp spring ID locators, Comp 10 degree locks. The hardware setup in these heads is for use with hydraulic flat tappet cams. Below is a detailed breakdown of the hardware used in these heads. We do offer these heads set up for all types of cams. See our other listings. Notice the multi angle valve seat cut. These heads are designed to very high standards. The AFR 335 heads pictured above are designed much like the high end heads on the market.  Pictured below are the AFR 335 heads in bare form to give you a view of them without the hardware from a different angle. The heads in this sale will be fully assembled. We know of many sellers of aluminum high performance heads that claim to use good hardware. Chances are they don’t know the difference between low grade and high quality hardware. Failure to follow proper assembly procedures and the use of low grade hardware are what cause most problems. Good quality hardware and proper installation can determine how well the heads will function and hold up under hard use.  There is a vast amount of low grade hardware on the market at this time. Much of this no-name hardware is completely out of spec, and made from inferior materials. It will fail sooner or later, but prior to it failing, this garbage hardware will perform poorly. Many of the low priced heads on the market have such hardware in them. It’s not enough to ask them what brand hardware they use because it would be impossible for you to distinguish it from one brand or the other by simply looking at it.  The best we can do to prove what hardware were using in our heads is to post our invoices from the branded name companies that we purchase it from. Our invoices will show huge purchases of every bit of hardware used in these heads. High grade hardware is nearly double the cost, but we know for a fact that this is very important for the performance and longevity of a set of cylinder heads. Consider what happens should an engine drop a valve into the combustion chamber at any rpm. Complete destruction of a large portion of the engine is a great possibility. That’s a worst case scenario, but there are many other problems such as poor performance and damage to cam and lifters that can occur.     Valve size 2.250 and 1.88. These heads have the correct seat diameter to allow use of these valves. These are true multi-purpose heads for street, drag race, and power boat applications. This set is an excellent upgrade over OEM cast iron heads on your big block engine. We honestly feel there is not a better set of heads for the price. These heads are tried and proven. The intake runner volume is 335cc, and the combustion chambers are 123cc.  You can reduce your engine weight by around 100 lbs. with the use of aluminum heads. You can also increase your power up to 250hp over an OEM 454 engine, depending on choice of cam and intake manifold. Compression ratio must be approx. 10.5:1 or higher on 454 engines. 496 or larger engines can get by with less compression but no lower than 10:1. Do not even attempt to use these heads on 427, 454, 496 engines with flat top pistons unless your running a blower or twin turbo setup, as they will not have near enough compression ratio to operate correctly.  We do our own assembly on our heads. See details below about our hardware and assembly procedure. We also offer variations of these heads for use with all types of cams. Be sure of what type cam you plan to run before purchasing. Read the ad completely before purchasing. The horsepower gain from the weight reduction of aluminum heads alone is noticeable, not to mention the fact that aluminum heads will allow you to run a bit more compression without the risk of detonation. The benefits are many to running aluminum heads. The most expensive cars in the world all run them. There are no drawbacks!   Tech support is available. We are confident that we offer the best advice in the business. We also offer these heads in bare form, as many customers have selected a machine shop of their choice, as well as their own hardware. We hope you will check out our other listings for the many other items we have available. The AFR 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 Below are the actual flow numbers for the 335cc AFR heads. These numbers are true and accurate. The testing methods we use are considered to be on the conservative side. Some choose to show flow numbers for their heads that have been done in a way that shows numbers that are misleading in our opinion. Rather than base a set of heads on flow numbers, you would be much better looking at the horse power numbers they make, providing the dyno numbers are true. We now use the AFR heads on most all of our bbc engines builds all the way up to the 572 engine. The horse power numbers they produce are exceptional as compared to any of the low to mid range priced heads on the market. We have yet to have one customer complain about these heads not making the power they expected or the build quality, and hardware used. The runner size of these heads has been verified by us. They are correct as stated, 335cc.  Intake Flow Exhaust Flow .100 .200 .300 .400 .500 .600 .700 73 145 215 285 320 345 360 .100 .200 .300 .400 .500 .600 .700 71 120 165 200 228 249 266 Here is a rundown on the hardware used in the AFR 335 heads and the assembly process. PBM/Erson Competition Series Valves. The retail cost at most High Performance stores on the PBM Competition valves is $239 Notice in the picture below the concaved face of the valves. You will only see this on high end valves. Most other valves are either flat faced or have a dimple in the center.   The pictures below show our PBM valves installed in set of CNC’d combustion chamber heads. This is not actual combustion chamber of the PC heads. The pictures are to show you the valve face design.     Pictured below on the left is the PBM competition valve, and the other pic. is of our conventional style valve. It was difficult to show the back-cut feature in the picture, but note that the valve on the left has a third radius cut.        We are now using the Competition Series PBM valves in all of our engines. These are considered a high end valve. These valves have an undercut and backcut feature. The backcut feature reduces valve weight by an average of 12.5 grams per valve. This weight reduction of approx. 220 grams off the complete set of valves has a monumental effect on acceleration, deceleration, and valve train life. It may be difficult to understand how this works, but rest assured, this is a huge reduction. The valve spring compression and rebound action will remain stable for a much longer time running lighter weight valves, as well as reducing valve float.  The backcut feature is not be mistaken for undercut. These valves have both features. Backcutting is an additional radius, but located on the head of the valve to increase the flow numbers and reduce valve weight. The flow increase is approx. 3-6 points on the flow bench, and possibly more, depending on the initial flow rate of the heads.  According to one of our machinists who built Winston Cup engines for 15 years, the exhaust valves had an additional radius cut on the outermost edge that allowed a better escape of the exhaust gas. This cut on the exhaust valve is in addition to the back-cut feature. The competition series are made from a much higher temp alloy than most other stainless valves. There are at least three levels of stainless valves on the market, excluding those used in very high level racing such as pro-mod. The PBM competition series is compared to the highest level of those three. As a final note, backcutting a set of valves is said to improve flow in the low lift area, and this is most desirable on street rods.  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.  Melling High Performance Dual Springs. Our Melling springs are 1.46 diameter, with an inner spring and internal damper. Melling springs are made in the United Kingdom by a factory that is fully owned and ran by Melling. All of our engines using the AFR bbc heads use these springs. Spring failures are near non-existent.  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.  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.    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.  Below is an excerpt from two of our Super Pro Street bbc 572 engines and solid roller cam ad that uses these AFR/Bravo heads. This can give you an idea of what these heads are capable of on a 572 bbc engine build, set up to run on 100 octane fuel, with a compression ratio of approx. 12.1:1 We have sold many engines with these heads. These heads, coupled with a single plane intake, have made up to 823 horse power at 6100-6200 rpm with the solid roller cam mentioned below. Further down are some of our pump gas combos using milder hyd. roller cams for all around street rod use. Your results will vary depending on the size and type cam you have, as well as the compression ratio and engine size.  Part number: 11-000-9, Spec card # 48558 720/715 lift. 276/286 duration 112 lobe sep.  Max power will be achieved at approx. 6200 rpm and will produce right at 822 hp.   Engines using this cam with the AFR/Bravo heads should run a stall converter in the 3000-3500 rpm range. Final gearing when used in a car or sport truck could actually be in the 3.55 range or numerically higher. This cam would be most suitable in vehicles weighing no more than 3800 lbs. This cam does not develop a high rate of vacuum.  Below are our dyno results on two of our 572 Super Pro Street engines using this cam. Your results may vary depending on carb choice. Dominator carbs will always out-do the 4150 style carbs in top end horse power. We also used our AFR/Bravo bbc heads setup with our Comp solid roller springs, # 919. We also strongly recommend our Pro Sportsman .300 tall solid roller tie bar lifters # RL979. We offer these springs and lifters in our other listings. Do understand these dyno reports are examples of of what the Bravo heads are capable of with different cam and compression setups and various size engines.  Version 1 of our 572 Super Pro Street engine. This engine is available in three different configurations. All three will have the same cam and cyl. heads. The differences are outlined with each dyno report. Our highest hp version comes equipped with a single plane Profiler intake that requires a 1050 Dominator carb. This engine will produce approx. 868 hp, and requires race fuel. This engine had 30cc dome pistons in it, and comp. ratio was in the 12 to 1 range requiring race fuel.  The potential of the 572 Super Pro Street engine is much greater than what you see above with a improved fuel delivery system. The Profiler intake and a Holley 1050 Dominator carb brought the HP numbers up to 868. This only increased the rpm by 200 over the regular setup. 6500 rpm making 868hp is very impressive to say the least. No additional drama brought to the engine other than a couple hundred rpm and about the use of a Dominator carb. Official Dyno Results of our Super Pro Street 572 engine using this cam with a single plane intake, AFR/Bravo 335 rectangular port heads, Brawler 1050 carburetor, and MSD distributor.   Official Dyno Results of our Super Pro Street 572 engine using this cam with a single plane profiler intake, AFR/Bravo heads, Brawler 1050 carburetor, and MSD distributor. Cam info: This cam is our official cam choice in our Super Pro Street 572 bbc engine. It is the perfect size to offer the best balance of power. Considering that we made this power with our AFR heads makes this cam a perfect choice for a super pro street rod or mild drag car. It makes a great amount of overall power on bbc street rods. This is an amazing cam in every respect. As you may know, there are many aspects to a cam’s profile besides lift, duration and lobe sep. and Comp Cams has produced an excellent cam that works very well in all bbc street rods. NOTE: the engine this cam was tested in runs on 100 octane, NOT pump gas.  This recent testing we have done with our special grind cams has proven that the AFR/Bravo 335 heads have the ability to make huge horse power numbers with the use of streetable cams, and safe compression ratios for use with pump gas. We recommend checking out our BBC engine ads for the full story on what to expect from these heads. We now use the AFR 335 heads on all of our 496/505 and 540/555 engines. The 496/505 street rod dyno results are amazing.  Below is an excerpt from a couple of our bbc engines and one our most popular bbc cam ads that uses the AFR/Bravo heads. This can give you an idea of what these heads are capable of on a common bbc pump gas engine build, set up to run on pump gas, with a compression ratio of approx. 10.1:1 This cam has been very popular for us, and is perfect for most bbc builds. We have sold many engines with these heads. These heads coupled with a single plane intake have shown to make 762 horse power on a pump gas 572 at 5900 rpm with 10.2:1 compression ratio and 736 horse power at 5900 rpm on a pump gas 555 engine with 10.1:1 compression ratio, using a new special custom grind cam that is only 575 lift. We will soon be testing these engines with a one step up cam size to see what the max potential of these heads are. Check out the dyno reports below.  This recent testing we have done with our special grind Comp cams has proven that the AFR/Bravo 335 heads have the ability to make huge horse power numbers with the use of streetable cams, and safe compression ratios for use with pump gas. We recommend checking out our BBC engine ads for the full story on what to expect from these heads. We now use the AFR 335 heads on all of our 496/505, 540/555 and our 572 bbc engines. The dyno results are amazing.  Comp Cams OE HYDRAULIC ROLLER 575/575 Lift 254/260 Duration 112 Lobe Sep. Xtreme Marine Camshafts 01-461-8 This cam has a step nose for use in oe roller blocks. Part number: 01-461-8 575/575 lift. 254/260 duration 112 lobe sep. This cam is our most popular choice for our street rod bbc engine builds. Comp Cams ‘Xtreme Marine & Auto’ Step Nose Hydraulic Roller Camshafts. Cam info: This cam is one of our official cam choices in our line of bbc engines. It is the perfect size to offer the best balance of power while putting a relatively low amount of stress on the valve train. This profile is somewhat easy on the valve train, it makes a great amount of overall power on bbc street rods. This cam is suitable on 496 bbc engines or larger. It’s has a very aggressive nature in the 454 sized engines and would require around 11:1 or higher compression ratio, but becomes more manageable in the 496 or larger builds. Compression ratio in a 496 engine build would need to be 10.5:1 or higher to yield decent results. This cam would be considered outstanding in a 540 and up to a 572 street rod build. 10.2:1 compression ratio or more would be all that is needed to obtain great results on these engines in a street rod.  This cam has a very unique profile. Our former cam used in our 555 engine was nearly identical in lift and duration and had a 110 lobe sep, and it made approx. 35 hp less on every combo we ran it on. Our new Comp cam is setup with a 112 lobe sep, yet still makes so much more power, and with the 112 lobe sep, creates a safer setup overall for the engine than a 110 lobe sep. This is an amazing cam in every respect. As you may know, there are many aspects to a cam’s profile besides lift, duration and lobe sep. and Comp Cams has produced an excellent cam that works very well in all bbc street rods. We’re going to list below our actual dyno results on every size of bbc engine we have dynoed with this cam. We have used it in at least 600 bbc engines, from a 496 up to our 632 in the past couple years. Of the three Comp Cams we use, this is our most popular by far.  We offer two more amazing Comp cam profiles that we’re very proud of. For those running the smaller bbc engines or lower than normal compression ratio, we recommend our cam one size down for improved low end response. If you’re building a 454/468 engine, this cam would be considered slightly aggressive, and would require compression ratio numbers in the low to mid 11’s to operate well. For those building a 496 or larger and want the very best mid to top end power available in a hydraulic roller without having to spend huge amounts of money to stabilize the valve train, then this cam is the perfect choice for you. This cam will allow safe operation of the valve train without spending a huge amount of money on valve train components. It’s not going to give any problems in the long run if you’re running decent hardware and lifters. You must run a higher than normal grade lifter such as our Max Effort Series. This increased lift and duration will bring the spring pressures up on the nose somewhat high, and that’s desirable to maintain valve train stability. Official Dyno Results on this cam in our 572 pump gas engine with a single plane intake and new AFR/Bravo 335 rectangular port heads. Compression ratio was 10.1:1 Cam used was our Comp 575/575 lift hyd. roller. Official Dyno Results on this cam in our 540/555 pump gas engine with a single plane intake and new AFR/Bravo 335 rectangular port heads. Compression ratio was 10.1:1 A solid 45-50 horsepower gain over the Procomp 320 bbc heads, all things equal. Actually all things were not equal. The New AFR 335 heads have 123cc combustion chambers, versus the Procomps 119. The compression ratio of this engine was down a good notch, yet still made nearly 50 hp more over the Procomp heads. Official Dyno report on our 496/505 engine with cam choice # 1 and a single plane intake, runs on pump gas. 674 hp with our new AFR/Bravo 335 heads is outstanding. This 496/505 engine only had approx. 9.85:1 compression ratio. Normally we run right at 10.3:1 Our hp numbers would have been higher for certain had we had the compression ratio in the higher zone. We fee this to be the perfect street rod head and cam combination for the popular 496 engine build, and will operate on pump gas with ease. We would like to see the compression on the 496 builds at 10.3:1 or more. We know the heads and cam are capable of producing more power had this particular engine had a bit more compression.   Official Dyno report on our 496 engine with cam choice 1, AFR/Bravo heads, and a single plane intake. 681 hp with our new AFR/Bravo heads is outstanding. Notice this engine has our popular 575 lift hyd. roller cam in it also. These heads are outstanding.   Official dyno report on our 496 engine with cam choice .575/.575, AFR/Bravo heads, our new Brawler carburetor, and a single plane intake. Official dyno report on our 572 engine with cam choice #2, AFR/Bravo heads, our new Brawler carburetor, and a dual plane intake. NOW READ THIS AMAZING DYNO REPORT ON OUR NEWEST PRO-STREET 572 ENGINE, RUNNING ON PUMP GAS. YES I DID SAY PUMP GAS AND MAKING 830hp @6400 RPM. THIS IS ABSOLUTLY THE BEST RESULTS WE HAVE EVER SEEN OUT OF THESE HEADS, CONSIDERING IT WAS DONE ON A STREET ROD ENGINE WITH 10.7 to 1 COMPRESSION RATIO. 14.5cc DOME PISTONS, 123cc AFR/BRAVO HEADS. HYD. ROLLER CAM WITH SOLID ROLLER LIFTERS, (HYBRID VALVE TRAIN)  Below are our dyno results on our newest version of the 572 Pro Street engine. Your results may vary depending on carb choice. We will be testing this engine with various carbs to obtain the best results. We found the Holley Ultra XP 950 to be an amazing carb for this engine. Considering it’s only 950cfm and made 830hp on this engine tells us that it’s about as good as it gets. We will continue testing with other carbs. The Holley Ultra XP is rather expensive but it is top of the line. Our next test will be with Quickfuels’s top of the line Q series carb, and then were going to try a custom built Pro-Systems carb. Last but not least will be the low cost Quickfuel Brawler carb. These carbs are about $350.00 less in cost but if we can achieve close to our target HP numbers, then it may be worth considering. Many factors are to be considered when selecting a carb, but the Holley appears to be a great choice on this high level engine.  Official Dyno Results on this engine in our NEWEST 572 pump gas PRO STREET engine with a single plane intake, AFR/Bravo 335 rectangular port heads, Holley Ultra XP 950cfm carburetor, and MSD distributor. We have also ugraded the intake manifold to the Holley Track Warrior Intake with the 4150 flange. This engine also has a one step bigger cam with more lift and duration. Below is our former Pro Street 572 Engine. The difference in this engine and the improved HP version above is the cam, and intake. Compression ratio remained the same. 10.7 to 1 Let it be understood that the former setup will have better drivability on the street. and is more suitible for very heavy cars and sport trucks, or vehicles that will be driven more than normal. Guide plate recommendation. We strongly recommend the use of the Dart adjustable guide plates with these heads, or with any BBC aluminum heads for that matter. These guide plates will allow better rocker tip alignment due to the fact they are fully adjustable. We use them on every set of BBC heads we install on our engines, including the Dart Platinum Pro-1’s, and AFR heads. The rocker tip may end up offset to one side more than is acceptable when using fixed guide plates, and the Dart adjustable guide plates allow a decent amount of correction. The variances in stud position to valve guide alignment vary on all brands of heads. The rockers could also contribute to this issue, as the trunnion or rocker body could have variance. 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. The part number for these guide plates is BBC-ADJ-GP. See our other listings for these items.  Pushrod recommendation. Do not use 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. They will most likely be the wrong length. 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. Pushrod length must be determined with a pushrod length checking device. We have a variety of sizes in our other listings. 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. We also offer pushrod length checking devices. 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 high quality USA made, Howards brand pushrods made from 4310 chromoly. They are superior to any stock pushrod. Our prices on them are the best you will find. You will see many low cost pushrods on the market, but these are totally unsuitable for use with these heads for the many reasons mentioned above, and they are not guide plate compatible. These pushrods will cause problems when used on a high performance setup. 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. The correct ARP rocker stud part number to use with these heads is #100-7101. See our other listings for these parts.  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/Comp 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.  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. SPEC INFO AND RECOMMENDED ACCESSORIES FOR FOR THESE HEADS.  Intake Gasket: Felpro 1275-5 For rectangular these heads. These intake gaskets have a glove like fit on the Bravo 335 heads when using a single plane intake. The 1274 seems to work well with most dual plane intakes.  Intake Port volume:              335cc Intake Port Dim:                     Int Port Location:                  Stock Intake Valve Dia.:                  2.250″                                           Exh Valve Dia.:                      1.880″ Exhaust Port Dim:                   Exh Port Location:                 Raised approx. .250 thous.  Exhaust Gasket:                    Depends on what type exhaust you’re using. Best to try and match up the gasket to your header or exhaust manifold Head Gasket:                         See the detailed info above for recommendations.  Head bolts:                            BBC-50 Head bolts, or ARP 135-3607 Head bolts or our BBC-75 Head stud kits.   Manifold:                               See the detailed info above for recommendations. Milling:                                  Max. .060 Scroll down to see info in this listing for details on this.        Pistons:                                 Most stock or aftermarket pistons. Our Wiseco pistons combine perfectly with these heads. Push Rod length:                   Pushrod length must be determined with a pushrod length checking device. We have a variety of sizes in our other listings. 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. We also offer pushrod length checking devices. Push rod Guide Plate:           We strongly recommend Dart adjustable guide plates. These are included. # BBC-ADJ-GP. Rocker Arm studs.                ARP 100-7101 Do not use off-shore rocker arm studs. ARP only. Not included. See our other listings. Retainers:                             Steel 10° Comp brand machined locks are used on all of our heads.  Spark Plug:                           Straight, .750″ reach, gasket, Autolite  3923 or NGK 4544 for one step lower heat range. See our other listings for these. Spring Pockets:                    1.550″ OD (.030″ deeper max) Springs:                                Melling 1.46 outer diameter, setup for hyd. flat tappet cams.                                               roller cams.                                           Valve Length:                        .100 over intake valves, std length exhaust valves.     Valve Stem Dia:                     .3415″   –   11/32″ Valve Train:                           STD BBC 7/16” stud mount Valve Guides:                        1/2″ OD   Int = Mag-bronze      Exh = Phos-bronze (.002″ press) Valve Guide length:                        Valve Guide clearance:         .0014″ – .002″   (with our .3415 dia. valve stem) Valve Guide Spacing:          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:                            Torque:                                  Head Bolts = 65-70 ft/lb                                               Rocker Studs = 50 ft/lb                                               Manifold = 35 ft/lb Block Use:                             Any BBC, GM OR DART Iron or Aluminum   Weight:                                 70-72 lbs fully assembled pair.

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.