Hey guys I am turning my car into a mild drag car to have fun with every now and then. I am going to build up a stong 350 for it. I just got a 4-bolt block I am going to use. I plan on using the stock crank, h-beam rods and some 12:1 forged slugs, Now I am going to be going with an undecided solid roller cam and I was wondering what race heads are out there that would be best for making 525-550 horse at the crank? Thanks for any advise guys...

AFR and Brodix both make great heads.

Probably wanna invest in a steel (or at least cast steel) crank if you plan on that kinda power. I have pro-1 heads and couldnt be happier.

Now the Brodix Race-Rite heads I was looking at and they seem to be a great deal for 1,300 bucks. Now with these heads and the rigth cam am I going to have a hard tiem with around 550 horse?? thanks

With 12.5:1, you shouldn't have a problem making 550. I would consult Crower for a good cam, and you could make 600 ish.

The race rites are a nice head for the price. If you're looking for 500+hp you should think of a stroker. For one, you'll want to get rid of the factory crank for that kind of power so you might as well get a 383 crank, rods and pistons. You said you're going with aftermarket rods and pistons anyway so it wont be any more money to buy a stroker kit. Only additional cost would be clearancing the block for stroker clearance which isn't much.

500-520 wouldn't be out of the question, but 600 ish is a bit optimistic. You'd have too much cam to be driveable. Afterall, you said a "Mild" drag car . One of the last 383's we put together went in a '72 nova. 5.7" rods, eagle crank and 11.2:1 CR. with AFR 195's and a 236/242 cam. Made 515 on pump gas and runs 11.5x's on radials. He drives it to work on a regular basis too

its gutted with a cage, it never gonna see the road again i am just not getibng into serious drag racing... so streetability is not an issue. I would rather keep it a 350 and just get a new forged crank...

You can make your target hp with a 350 but it will have to rev higher than say a 383 or 400 to do it.

You'll want a head that flows 260+cfm a port size of 180 to 215cc is about right. you'll need a fairly big solid or roller cam. 250 to 265@.050" and near 600lift or more.
A single plan intake (vicJR)
big headers 1.75" best. If you want to run race gas than more compression the better, but a 12.5:1 motor will not run on pump gas. Decide what you want and build accordingly

you can built it for either.
Plan on 10.5:1 for iron heads and 11:1 max for aluminum.
(94 octane)
A 750cfm carb reworked to 820cfm is about right.

The Racerite heads are good as they come out of the box but really are ment to be ported to get the flow you want.
A brodix track 1 can be ported over 300cfm. so can a Dart 200 or 215 head.
A edelbrock vic jr head falls in that class too.

Plan on a 260+cfm head and a 7000rpm +capable valvetrain

race converter and high rear gear ratio.

I like the brodix 18 deg heads... make tons of power and use conventional 23 deg valve train. Needs 18deg pistons
and custom headers. but easy 700hp same $$$

a 400ci based motor will make a ton more torque and meet or exceed the power of a 350 and ultimately last longer for the same or simular $$$ investment. (Lower rpm)

The "12.5:1 forged" slugs are your first mistake

You want to build a high compression 350 motor with "flat top pistons" block decking and small chamber heads.
this is the way to make reliable power. the high dome 12:1 pistons are for the 60's

You can build to 13:1 using flat tops with the right headcc and machining.
you can do this with the cylinder heads you have right now but they will need larger valves and a full port job. to 270cfm

dart pro1's outa the box and a solid roller in the 630 lift range on a 106 lobe with around 250 duration at 50 should get you there with 12 to 1. afr's or brodix for sure will get your there. all aluminum heads, dart iron heads will need alot of port work to get there.

If you really want a "Mild" 350 that makes 500+hp, you could just supercharge what you've got now.

A 6.71 blower with two 750's bolted on your motor, with 10lbs of boost and race gas or methanol would make 500hp all day long and live forever.
Wouldn;t have to start over. don;t need to rev it any higher than you are now.

You'd want to reduce the rear gear ratio.

a whole lot simpler cheaper and reliable.
Nothing says look at me like a 6.71 blower pokin' thru the hood.

A typical 6.71-8.70 blower manifold can be modified to bolt on to your vortec heads. They have lots of meat on the intake flange.

I think BDS or Dyers may have a bolt on manifold now.

Buddy of mine has a 400sbc with AFR 195s and it makes 365rwhp... thats roughly 500 crank i think?

no thats roughly 430 flywheel.

[b]

If you are going to buy a crank, then buy a 3.75 stroke crank, and go for the 383. I would never give up cubes if a new crank is on the list. You would be suprised of how close in price the cranks are.

That was suggested to him, but he wants to build a 350. But I'm confused, you don't want to get big into drag racing but the car is gutted. Streetability isn't an issue but you want to build a mild 350.

Yea, I agree. "MILD" and 525-550 horsepower, dont belong in the same sentence together. That kind of power will push a stock weight F-body into the mid to low 11s.

check my sig. It will help you go in the right direction. Those, numbers where done on 92 octane from a 76 station .

500 isn't as difficult as it used to be with the selection of aftermarket heads available these days. Over that, though, and you better find a shop that knows what they're doing porting heads and selecting a cam to match.

For right around 500 HP you could go with some AFR 195s and a well selected solid roller with about 230-240* duration. With a good-flowing single plane intake and good flowing exhaust you could be around 500, maybe a little over, especially if you run the exhaust uncorked at the track. And you wouldn't need a towering 12:1 compression ratio to do it, either. 10:1 would do fine so you could run it on pump gas.

THEN..... a separate fuel cell for race gas to feed..... the nitrous system! A little 150 plate shot on top of that and now you're well over 600HP.

That's the beauty of nitrous in a dual-purpose car. A relatively modest and streetable engine for tooling around on the street and then it becomes a beast when it's time to get serious.

383
Eagle forged crank/rods
Venolia foged pistons
Out of the box AFR 195 CNC'd
Comp 236/242 cam
Air Gap intake
Holley 650 DP, half shafted, milled off the choke horn and ported the main body a bit, flowed 690 CFM (superflow bench)
Internally balanced and fully blueprinted.

The motor made 515hp/565tq on PUMP GAS with 11.2:1 cr on our Stuska engine dyno.

You'll want to find a shop that knows what they're doing if you're trying to get every hp out of the motor. All of the small things that make a few HP here and there add up. Metric ring packages, zero decking, touching up the chambers, square decking all adds up and makes the difference between a machinist and an engine builder and also the difference between a $1200 crate shortblock and a$3500 custom shortblock.

18* heads (or better.... 15s would be nice, but the cost is significantly higher because of the valvetrain pieces)
have them ported well... not hogged out, but finished nice.


aim for 10.8 to 11:1 compression with the piston out of the deck a hair and flattops (with valve releifs).. get a modern chamber and good quench and you'll still be able to run pump gas.


you said mild... so ditch the soild cam.. you're either building a racer, or a driver.. a racer doesnt use the word mild. a driver doesnt want to relash his valves every 3 weeks.

put a good hyd roller in.

run a nice aftermarket fuel injection system.


if you do all this right, and it will sound mean at idle, but drive smoothly.. get reasonable MPG, and make your 430ish rear wheel hp (aka 500 crank hp)
if you'd like more real world examples of this, look up "stock LS1 with a big cam" online.

the only secret to this is good heads... good heads and dont go overboard on the cam.