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3349 E. Stone Dr.
Kingsport, TN 37660

BBC - AFR Enforcer 335cc

$1,867.76

Available


Variants:

Solid Roller Cam (up to .740" lift) [8000-BBC-ENFORCER]
Hydraulic Flat Tappet Cam (up to .580" lift) [272-BBC-ENFORCER]
Hydraulic Roller Cam (up to .620" lift) [274-AFR-ENFORCER]

AFR-1400x600_(2)

AFR 335cc Enforcer Heads

This sale is for a set of heads (2 heads). 123cc Combustion Chambers and 335cc runners.

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. See the "Hardware" tab for more details.

The AFR Enforcer 335 BBC Rectangular Port Heads are perfect for 454, 496, 540, and 572 street/strip engines. We now use these heads on our 505, 555, and 572 BBC builds.

They produced an impressive 762 HP with our Comp .575" lift hydraulic roller cam and a single-plane intake manifold on a 572 pump gas build. We estimate around 650 HP on a 496 build with the same mid-size cam.

None of the low-cost BBC heads on the market offer this level of performance, as far as we know. Fully built with premium hardware, these heads come ready to install.

Our cylinder heads are made from AC4B alloy, tempered to T6 standards. More details about this alloy can be found in the lower section of this ad.

Flow Numbers

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

Example Results

Check out our dyno results tab, featuring these heads on our BBC 572 Pro-Street engine. We hit 830 HP on pump gas! It's incredible that these heads can move so much fuel and air to produce this kind of power in a pump-gas street rod engine. This is our best horsepower on a pump-gas setup to date—and who knows how much more these heads are capable of.

We've achieved approximately 875 HP on a race fuel setup (12:1 compression ratio) with a Dominator carb. I would say that's probably their limit, but we can't be sure yet. Considering these heads only have a runner size of 335cc, they’ve proven to be the best heads for the money we've ever offered.

Compatibility and Compression Recommendations

These heads are not suitable for 396 or 402 engines with a bore size smaller than 4.250". The larger 2.250" intake valve on these AFR heads can interfere with the cylinder wall in those applications. However, these heads are ideal for BBC engines with a 4.280" or larger bore.

We recommend a compression ratio of 9.8:1 to 10.5:1 for pump gas, allowing you to take full advantage of the aluminum castings.

Why We Chose the AFR 335 Heads: Superior Performance and Value

We certainly know where to draw the line with lower-end products and continue to eliminate parts that we once accepted but no longer carry for various reasons. Sometimes, it's not that a particular product has had issues; rather, something better simply comes along. The AFR 335 cylinder heads are that "something better."

Given that the price is only slightly higher than our previous line of heads, these are easily the best value we've ever offered. The performance has been outstanding on every combination we've tested them on. In the rare event you encounter issues with these heads, we will address the problem promptly. So far, problems have been non-existent.

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.

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.

Genuine ARP Rocker Studs and COMP Adjustable Guide Plates Included

COMP Cams Adjustable Guide Plates

973b9ecf-50a4-4443-bc32-bfb9cc6beda5

ARP 7/16" Rocker Studs # 100-7101

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ARP 7/16" Rocker Studs # 100-7101

Installed:

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Notice the multi angle valve seat cut. These heads are designed to very high standards.

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More pictures below of some the details on our new AFR Enforcer heads.

INTAKE_PORTS_AFR_(3)

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.

20220311_121248_(3)

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.

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Recommended Intake Gaskets

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

Recommended Head Gaskets

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.

Multi-Angle Valve Seat

Notice the multi angle valve seat cut. These heads are designed to very high standards.

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The AFR 335 heads pictured above are designed much like the high end heads on the market.

Top Grade Hardware

We know of many sellers of aluminum high-performance heads who claim to use quality hardware, but chances are they don’t know the difference between low-grade and top-tier hardware. Most issues stem from poor assembly procedures and the use of substandard components. Quality hardware, paired with proper installation, is critical to ensuring the heads perform well and hold up under hard use.

There’s a flood of low-grade hardware on the market right now. Much of this no-name hardware is out of spec and made from inferior materials, leading to poor performance and eventual failure. Many of the low-priced heads you’ll find out there are filled with this kind of garbage. Simply asking what brand hardware they use won’t help, as it’s impossible to differentiate quality by sight alone.

To back up our claims, we can post invoices from reputable suppliers that show we exclusively use high-grade, branded hardware in our heads. This premium hardware costs nearly double compared to low-grade alternatives, but we know it’s essential for performance and longevity. Just imagine what could happen if an engine drops a valve into the combustion chamber at high RPM—total engine destruction is a very real possibility. While that’s a worst-case scenario, other issues like poor performance and damage to the cam and lifters are all too common when using inferior parts.

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.

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Reduced Weight, Increased Power!

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.

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!

Help!

Tech support is available. We are confident that we offer the best advice in the business.

Bare Heads

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.

AC4B Alloy

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

Here is a rundown on the hardware used in the AFR 335 heads and the assembly process.

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PBM/Erson Competition Series Valves.

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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.

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Pictured below on the left is the PBM competition valve, and the right 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.

pbm 11-16 photo 72c1556b-5ac1-4332-9512-01f8204a73a5.jpg

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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.

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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.

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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.

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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.

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.

572 SUPER PRO STREET photo Image 11 1.jpg

572 SUPER PRO STREET photo Image 12 1.jpg

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.

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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.

572 SUPER PRO STREET photo Image 11 1.jpg

572 SUPER PRO STREET photo Image 12 1.jpg

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

575/575 cam, bravo, brawler 950 photo 45abb366-9a68-481d-acc3-b1dec2442e55.jpg

575/575 cam, bravo, brawler 950 graph photo d20741ff-df9f-41c4-a0c6-2b482950d6e2.jpg

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.

Product Information

Product TypeCylinder Head
Price (excl. tax)$1,867.76
Price (incl. tax)$1,867.76
Tax$0.00
Availability Available
Block BBC
Brand Air Flow Research (AFR)
Stud Girdle Included No
Exhaust Port Location Raised approx. .250"
Exhaust Valve Diameter (in) 1.88
Head Bolts BBC-50 Head bolts, or ARP 135-3607 Head bolts or our BBC-75 Head stud kits
Intake Gasket Felpro 1275-5 when using a single plane intake. Felpro 1274 seems to work well with most dual plane intakes.
Intake Port Location Stock
Intake Port Volume (cc) 335
Intake Valve Diameter (in) 2.25
Milling

Max. .060". See description for details

Spark Plug Straight, .750" reach, gasket, Autolite 3923 or NGK 4544 for one step lower heat range. See our other listings for these.
Springs Melling 1.46 outer diameter,
Torque
Head Bolts
65-70 ft/lb
Rocker Studs
50 ft/lb
Manifold
35 ft/lb
Valve Guide Clearance .0014" - .002" (with our .3415 dia. valve stem)
Valve Guides 1/2" OD Int = Mag-bronze Exh = Phos-bronze (.002" press)
Valve Length (in) .100 over intake valves, std length exhaust valves.
Valve Seat Angles Int = 32° - 45° - 60° - 70° Exh = 37° - 45° - radius
Valve Seats Hardened Ductile Iron, .006" press
Valve Stem Diameter (in) .3415" - 11/32"
Valve Train STD BBC 7/16" stud mount
Weight 71
Push Rod Guide Plate We strongly recommend Dart adjustable guide plates. These are included. # BBC-ADJ-GP.
Retainers/Locks Steel 10° Comp brand machined locks are used on all of our 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.
Rocker Studs ARP 100-7101 Do not use off-shore rocker arm studs. ARP only. Not included. See our other listings.
Shipping Cost 25.0
Spring Pockets OD (in) 1.55
Valve Seat Dimension Standard
Number of reviews 0

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