Does anyone have some real data from the new head choices out there?

Coming into some cash, so I am looking at BBF heads to see which way I'm going to go on a new build. Several new heads out or coming out, but I'm not seeing alot of data yet. I have a block that is punched .040 over, a set of 6.7 aluminum rods and a set of long tube headers 2-1/4 into 4 set up for CJ ports. My goal for this build is to get into the high 800's or low 900's. Was thinking of going with a 4.5" forged crank to get a 547. So, I'll need to purchase the heads, pistons, crank and intake. This motor will be on mech. injected alcohol and I'm thinking 7200rpm max.

Being that your headers are cj , does that mean you are looking for heads that can use them?

Either use heads with a cj flange, or an adapter from the chev. bolt pattern.

Lem Evans wrote:Being that your headers are cj , does that mean you are looking for heads that can use them?

What Chassis? What are you building it for?

dfree383 wrote:What Chassis? What are you building it for?

Will be the primary mill for my F150 drag truck. (https://www.429-460.com/t16148-1995-f150-pro-street-project-thread)

A P-51 Head should get you to your goals.

Why not use A460 heads with adapters? I think that if you are looking to spend the money on new heads this would be the obvious choice. AFR heads have yet to be proven. The P51 heads are proven and would make the power you want. I believe that 800-900hp is relatively easy to accomplish with the cubes and A460 heads..

If you have not purchased or do not have anything for the topend the A460 setup is pretty close cost wise especially if you shop around.

Id look at it from the aspect of how fast do you wanna go and is this the last time you plan to purchase heads.

460pulling wrote:Why not use A460 heads with adapters? I think that if you are looking to spend the money on new heads this would be the obvious choice. AFR heads have yet to be proven. The P51 heads are proven and would make the power you want. I believe that 800-900hp is relatively easy to accomplish with the cubes and A460 heads..

If you have not purchased or do not have anything for the topend the A460 setup is pretty close cost wise especially if you shop around.

Id look at it from the aspect of how fast do you wanna go and is this the last time you plan to purchase heads.

Who makes adapters to go from a big block Chevy to a ford header?

In my opinion... if you are going to make a cylinder head choice simply based upon headers you already have then you sure have got your priorities totally mixed-up for making the power you expect.

Build the engine with correct parts and get some different headers; especially with a 4.500" stroke and 7,200 RPM..

460pulling wrote:Why not use A460 heads with adapters? I think that if you are looking to spend the money on new heads this would be the obvious choice. AFR heads have yet to be proven. The P51 heads are proven and would make the power you want. I believe that 800-900hp is relatively easy to accomplish with the cubes and A460 heads..

If you have not purchased or do not have anything for the topend the A460 setup is pretty close cost wise especially if you shop around.

Id look at it from the aspect of how fast do you wanna go and is this the last time you plan to purchase heads.

A460 was my first choice but I wanted to see if any of the new offerings would meet goal and let me keep my current headers.

rmcomprandy wrote:In my opinion... if you are going to make a cylinder head choice simply based upon headers you already have then you sure have got your priorities totally mixed-up for making the power you expect.

Build the engine with correct parts and get some different headers; especially with a 4.500" stroke and 7,200 RPM..

Randy, I am always getting schooled (and not afraid to ask dumb questions either), so I'll ask. Is 2-1/4 into 4 to small for this application? I have no problem going with new headers BUT, If I can build a stronger mill with the headers I have, then that is $1500 I don't have to spend. That is why I was thinking of using my existing headers.

dfree383 wrote:

460pulling wrote:Why not use A460 heads with adapters? I think that if you are looking to spend the money on new heads this would be the obvious choice. AFR heads have yet to be proven. The P51 heads are proven and would make the power you want. I believe that 800-900hp is relatively easy to accomplish with the cubes and A460 heads..

If you have not purchased or do not have anything for the topend the A460 setup is pretty close cost wise especially if you shop around.

Id look at it from the aspect of how fast do you wanna go and is this the last time you plan to purchase heads.

Who makes adapters to go from a big block Chevy to a ford header?

I was meaning re-flange the ford headers to a Chevy flange. It isn't the best way to do it but it is one way that it can be done.

New headers for A460 heads and I would do it. I don't see much of a comparison from a P-51 head to a A460 head. But it is all in where and how you want to spend your money to make X amount of power. One person may say to buy profiler heads the next will say C460 heads.

dfree383 wrote:

460pulling wrote:Why not use A460 heads with adapters? I think that if you are looking to spend the money on new heads this would be the obvious choice. AFR heads have yet to be proven. The P51 heads are proven and would make the power you want. I believe that 800-900hp is relatively easy to accomplish with the cubes and A460 heads..

If you have not purchased or do not have anything for the topend the A460 setup is pretty close cost wise especially if you shop around.

Id look at it from the aspect of how fast do you wanna go and is this the last time you plan to purchase heads.

Who makes adapters to go from a big block Chevy to a ford header?

I was meaning re-flange the ford headers to a Chevy flange.  It isn't the best way to do it but it is one way that it can be done.

New headers for A460 heads and I would do it. I don't see much of a comparison from a P-51 head to a A460 head. But it is all in where and how you want to spend your money to make X amount of power. One person may say to buy profiler heads the next will say C460 heads.

dfree383 wrote:

460pulling wrote:Why not use A460 heads with adapters? I think that if you are looking to spend the money on new heads this would be the obvious choice. AFR heads have yet to be proven. The P51 heads are proven and would make the power you want. I believe that 800-900hp is relatively easy to accomplish with the cubes and A460 heads..

If you have not purchased or do not have anything for the topend the A460 setup is pretty close cost wise especially if you shop around.

Id look at it from the aspect of how fast do you wanna go and is this the last time you plan to purchase heads.

Who makes adapters to go from a big block Chevy to a ford header?

I was meaning re-flange the ford headers to a Chevy flange.  It isn't the best way to do it but it is one way that it can be done.

New headers for A460 heads and I would do it. I don't see much of a comparison from a P-51 head to a A460 head. But it is all in where and how you want to spend your money to make X amount of power. One person may say to buy profiler heads the next will say C460 heads.

HorsinAround wrote:

rmcomprandy wrote:In my opinion... if you are going to make a cylinder head choice simply based upon headers you already have then you sure have got your priorities totally mixed-up for making the power you expect.

Build the engine with correct parts and get some different headers; especially with a 4.500" stroke and 7,200 RPM..

BUT, If I can build a stronger mill with the headers I have, then that is $1500 I don't have to spend. That is why I was thinking of using my existing headers.

Exactly what i said ... you wish to attain a certain power level and are asking about heads for that however, your PRIORITY is to use the headers you already have.

As I said ... the PRIORITY is mixed-up.
The quality rotating assembly and required parts to be able to consistently make power at 7,200 RPM with a 4.500" stroke will cost you more than $1,500.00 extra.

Do whatever you want to do ... those headers may have some kind of sentimental value as far as I know.

sorry ... double post

If you decide to go the P51 route....I have a pair in stock.

HorsinAround wrote:My goal for this build is to get into the high 800's or low 900's.

Lem Evans wrote:If you decide to go the P51 route....I have a pair in stock.

IMO,.......The P-51's are what I would go with if I was you.  
You shouldn't have any problem meeting your goals,..... providing you have enough Compression & Cam.

I agree keith. when this windfall arrives in a couple more months, I'll get them ordered. Compression and cam are not an issue as I don't have pistons or the cam bought yet. Based on Randy's insightful comments, I will probably just stick with the 4.3 stroke I was originally thinking about.

HorsinAround wrote:I will probably just stick with the 4.3 stroke I was originally thinking about.  

Why limit yourself on the stroke,......?

You'll be giving up roughly 40hp,......."IF" you stay with .040 over block   523 cubes vs 547.


If it was me,....
I'd bore it out .080 and install a 4.50 stroke crank,.......and have a 557

It's just going to make it harder to reach your HP goal, when you set a specific limit on cubes.


IMO,.....
I'd much rather have more cubic inches,.......and keep the RPM's down.   It's a lot easier on the Valve train,......and the Wallet.

Copperhead wrote:

HorsinAround wrote:I will probably just stick with the 4.3 stroke I was originally thinking about.  

Why limit yourself on the stroke,......?

If it was me,....
I'd bore it out .080 and install a 4.50 stroke crank,.......and have a 557

IMO,.....
I'd much rather have more cubic inches,.......and keep the RPM's down.   It's a lot easier on the Valve train,......and the Wallet.

I'd have to find a block that can be punched to .080. I have one that I got in a trade that is .040, and he said it was sonic checked to .060. I have another engine but haven't have time to tear it down to have the cylinder walls checked. Im going to keep looking though.

Is 6500 rpm on a 557 a realistic expectation?

HorsinAround wrote:

Copperhead wrote:

HorsinAround wrote:I will probably just stick with the 4.3 stroke I was originally thinking about.  

Why limit yourself on the stroke,......?

If it was me,....
I'd bore it out .080 and install a 4.50 stroke crank,.......and have a 557

IMO,.....
I'd much rather have more cubic inches,.......and keep the RPM's down.   It's a lot easier on the Valve train,......and the Wallet.

I'd have to find a block that can be punched to .080. I have one that I got in a trade that is .040, and he said it was sonic checked to .060. I have another engine but haven't have time to tear it down to have the cylinder walls checked. Im going to keep looking though.

Is 6500 rpm on a 557 a realistic expectation?

My previous engine (557) was a late model D-9 block, 10.8: compression, small cam &  2.30 valve A-head (unported) made 850hp @6300 / 775tq @ 4800

IMO,.....I really think you can better my old #'s (on a P-51 deal) IF,... you bump up the Comp about 4 points,.....and get Lem to spec you out a decent sized Comp Roller for it.

Copperhead wrote:

Why limit yourself on the stroke,......?
You'll be giving up roughly 40hp,......."IF" you stay with .040 over block   523 cubes vs 547.

If it was me,....
I'd bore it out .080 and install a 4.50 stroke crank,.......and have a 557

It's just going to make it harder to reach your HP goal, when you set a specific limit on cubes.

IMO,.....
I'd much rather have more cubic inches,.......and keep the RPM's down.   It's a lot easier on the Valve train,......and the Wallet.

Totally wrong ... TORQUE and HORSEPOWER are NOT the same thing. There will probably be absolutely NO horsepower increase at the flywheel using a given cylinder head with this longer stroke however, the torque peak and amount of torque below the peak WILL increase.
Over 90 feet per second average piston speed you will most likely go backwards unless you also have a proper intake system and lightweight rotating assembly.

The reasoning given for whatever YOU would rather do is just fine but, don't preach misinformation based solely upon your opinions.

ACTUALLY, with the slightly shorter stroke, (4.300" vs. 4.500"), the upper RPM limit will be about 5% higher maybe making slightly MORE horsepower along with a PEAK torque decrease.
Being able to REV it higher with more appropriate gearing will definately get more power to the wheels at Wide Open Throttle.

HorsinAround wrote:

Is 6500 rpm on a 557 a realistic expectation?

YES ... that is about the upper limit, to be able to spin it higher and continue to get better results with that 4.500" stroke gets EXPENSIVE.

rmcomprandy wrote:

HorsinAround wrote:

Is 6500 rpm on a 557 a realistic expectation?

YES ... that is about the upper limit, to be able to spin it higher and continue to get better results with that 4.500" stroke gets EXPENSIVE.

I was hitting the limiter @8000 last time at the track.

cool40 wrote:

rmcomprandy wrote:

HorsinAround wrote:

Is 6500 rpm on a 557 a realistic expectation?

YES ... that is about the upper limit, to be able to spin it higher and continue to get better results with that 4.500" stroke gets EXPENSIVE.

I was hitting the limiter @8000 last time at the track.

With a lightweight rotating assembly, using high compression with thin rings and a block with a stiff bore and a well done inlet, you can get there ... it certainly was not a regular lower cost engine assembly.