Dart 325 Pro 1 heads with the 2.30 intake valve.

 

really an open ended question....tons of good choices.

 

What's the price difference in iron heads and aluminum heads

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If you are going to build a 750HP - 509 big block chevy with iron heads it's not going to be a budget build. The iron EQ320 BBC heads with some work can get close but it's gonna take some special parts and work to get any iron heads up to that level of power. I think an aluminum head 509 will give you more compression and choices for the dollar and get you closer to 750HP with an easier less overall expense build. The savings in weight coming of the front of that heavy car won't hurt either. Go aluminum.

 

So 315-325 cc Heads will be good for that size engine?

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Yes. I wouldn't go any bigger. 325 if you really want to spin some rpm, 305-310 if you're going to keep it under 7500.

 

Forget iron. Take the weight savings of aluminum .

 

Will do

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Another vote for Pro 1 325 with the 2.30" valve. That head can be had with either 2.250" or 2.300" valve. No need to spend any money on porting. Just port match the intake. Edelbrock #2907 Victor R454 intake is also a good match. You can have a Brodix head a little cheaper but you want the 24 degree head with the 2.300" valve, not the older 26 degree heads.

 

Put and AFR 335CNC head on it....
if built right it'll make more then 800 on Pump gas.

 

Not necessary. Smaller head will make as much peak power and better average.

 

Down the I plan on going with some sort of forced induction. So the heads will have to be a solid performer in both naturally aspirated and a boosted application

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So you plan on swapping out pistons and then re-cam it when you change over to a boosted application?

 

88

IF your budget permits, the AFR 300 "roval" are a pretty nice go between head. Flows well out of the small port so velocity for street driving would be nice, yet flow up hi for when you're racing. A bit more then the 325's though...

 

565 on here with the AFR 300's

http://www.yellowbullet.com/forum/showthread.php?t=1591442

 

Those aren't even close to out of the box 300's.

 

Years ago I did a pump gas 509 for a guy with a 3600# Chevelle. Hyd roller motor, 4150 carb, mildly ported AFR305's, ported Vic Jr intake...engine made 764 @ 6200 and 732 tq @ 4900. The engine was a beast in that car...ended up with a best of 9.40 flat. Some compression, a solid roller and a little more rpm and that engine would be well into the 800hp range with really good tq and an rpm range that would work very well with a heavy car.

 

I know of a 509 ci 14to1 with BMF 330 heads makes over 800 hp at 7500rpm not sure how well it would run on Pump gas

 

I did a set of AFR 315's last year for a 515 (4.53 x 4.0). Gen6 block (from the 509 above) 13.2:1, did a 2.30 valve upgrade, bowls and short turns, ported Edelbrock 2907, Straub hyd roller on .903 Morels, Mark Jones built, made 896 @ 7100, 731tq @ 5500 on MS109. Has run the best of 9.07 @ 147, 1.26 60 in the same car as above, street legal 67 Chevelle, 3520#.

 

I am amazed sometimes on how some like you the OP on here think that building a 509 -750HP N/A pump gas engine is a walk in the park.

Horndog questions you are going to tear the engine back down, change the pistons, rings and cam and add boost and Whola you've now got a 509 pump gas boosted engine that will make well in excess of 750HP and have nice street manners.

Sir, excuse me but I think you are possibly kidding your self how easy and affordable this project is. You seem like a user who wants his cake and eat it too. You are here asking some good reasonable questions and getting some good answers from some smart successful racers and builders on here, but if you think you can build one type and size fits all uses, you've got a lot more to study and learning before you even start! Figure out how much you can afford to spend now and see if that will let you even build the 750HP pump gas 509 you are going to start with and then analyse if you will have the funds to pull the engine and do a major rework and refresh to get it to a point where you can boost the engine for more than 750HP and still run pump gas. Seems to me that a shot of nitrous might be a better power adder for your original build and still allow you the original power you're building for and achieve better power levels later. Even with this scenario you will need special components to make a nitrous shot reliable.

Don't buy your engine twice, make a plan for the build that will do all you plan to do and then make sure you will have the total funds it will take to getter done!

 

Ray, in 2017 it is quite easy to get a pump-gas burning 1.5Hp/inch motor, Ford or Chevy.

Look no further then Mark Jones. He is very good yet does 750+ 496's with OEM 781 ovals, which are quite good as well. My shop did a pump-gas 468 street roller and ported 840 heads and 163 intake that did over 700. Thats 1.49Hp/inch, so add the 51 inches???? There are plenty of pump gas 750+ Hp out and running now.

There was even a mild and inexpensive SB on here, less the $10,000 that made 750Hp. I believe it was around 420 inches but that I could be wrong. It can drive from New York to Detroit too. 750Hp street motors and now the 500Hp motors of the 90's.

 

it's the year 2017, building 1.47HP/cu.in IS a walk in the park. "affordable" though means different things to different people

 

I don't think 750 hp would be too difficult to achieve from a 509 incher. with 11.5 compression, a good single plane and the correct Camshaft as well as Carb. A little research on head choice would make someone pretty happy.

 

Umm, I see someone got up on the defensive of the bed this morning!!

Scott, it's all for the betterment of the thread, you have your views, I have mine and RCM has his. No one is saying either are wrong, just a different view, that's all.

Personally, I think the 300 head would be a very nice head on this 509 in the heavy car. OOTB I think, and Tony has stated it, it a better head than the 305. Now when you play with both, well now that get into attention to details and the experience of the porter.

Different ways to get results.

 

For quite a while now we've been building both 509's and 540's as "bolt-together" builds using the original Pro-Topline 320 casting and now the same RHS 320's. They use the 2.250" intakes and 1.880" exhaust's.

These are easy builds, absolutely no chasing HP numbers. All these type builds are under 10:1 and the 509's average 700 HP/620 Torque, the 540's average 750 HP/700+ Torque! We do much better still for the street guys on the 11:1 C.R. platform.

Almost all are on the retro-hyd roller platform and all peak under 6400.

Thanks, Gary in N.Y.

P.S. One other "positive, these castings are also preset up with intake rocker stud bushings, NO heli-coils. We find ourselves constantly repairing these intake stud holes on just about every other brand of heads, probably averaged 5 sets per year so far for the past few years!

 

We did a pump gas 509, Canfield 310's, 2.25/1.88, no porting, hyd roller, 850 DP on unported Vic Jr, 1" open spacer, 10.0:1, 710 hp @ 6200, 680 tq. @ 4800. Same as yours...very easy "bolt together" build.

 

I agree with RCM Afr or Dart 335 would be a good choice, gives some room for extra ci down the road.

 

I rebuilt a 532 that had AFR 385 CNC on it. It won a lot of truck pulls with out of the box heads and less than .900" lift cam. But it did turn some RPMs to do it.

Also rebuilt a 505 with Dart CNC 355 out of the box. It ran faster than it should have at less than 8000.

 

I'm sorry my post comments about the OP led some to believe that I was saying that 750HP BBC's are difficult to spec. and build.
There are thousands out there which are great performing successful builds.

What I was saying is that based on the OP's posts and the way he flips around a little in his discussion of his thoughts and statements I think he will have a harder time getting it right.

He is internet buying and building his supposed engine!

Goes to one of my favorite sayings. "A LITTLE KNOWLEDGE IS A DANGEROUS THING!"
Especially when building a 750HP big block!

 

Im gaining knowledge as I go. In the past I've only dealt with small block crate engines. All those was pretty much 350-383's. So I'm new to the big block. Since I bought my chevelle the only other engine that I was considering was a 496. I do a lot of reading on this site and there a lot of knowledgeable folks on here. So if I don't know something I ask. It's a lot of different options out there as far as engine combinations, so I try to find out as much as i can about the options that the more experienced guys give me

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Math will tell you exactly what head cross section you need to for a given rpm range. Depending on the width of the power band desired, wide or narrow, one can adjust the cross section to make the best power for the given rpm range. Using math to do this will carry the torque farther in the desired power band and in turn calculate more HP. Use math to your advantage in engine building, save the guessing for the lottery.