I'm building a 350 for my 86 z28. It,s a mid 70's 350 4 bolt main bored .040 over. I just bought a maf tpi set up with the an 85 lower intake. I plane on installing aftermarket runners. I would like to make 350 RWHP. What are the best set of aftermarket heads for a decent price.

 

I think you have to define "decent price." I am looking at this stuff myself and cheap vs. good heads are two very conflicting things.

A lot of people like AFR (air flow research) and Trickflow heads. I am considering AFR 195cc, but I think the cost of my engine (with these heads) will be an arm and a leg.

Look around, name a price. I am sure then more people will tell you what you can and/or should get.

 

for a "decent price", look into edelbrock's line of performer RPM and E-tec heads...they offer very good performance for their prices. AFR, trick-flow, dart etc. are top of the line heads but they cost top of the line bucks too.

 

I'm actually partial to ported L98 Iron heads . I have a local guy who will do a Stage III Port - claims 50hp increase. (30hp I, 40hp, II, 50+hp III) for $350.00 which is not bad at ALL. About $500 dollars in the heads total and you have some damn good sleeper heads that will compete with many aftermarket...

Anyhow...

You have set a high goal with that 350RWHP considering STOCK L98 only had 245hp at the crank...

Your going to need a few things:

1) Ported L98 heads (Highly), AFR's, Trick Flow or other decent flowing head.

2) Aftermarket Base/Runners/Ported Plenum.

3) 52 or 58mm Throttle Body.

4) LPE 219, LT4 Hotcam or similar Camshaft (Maybe ZZ9?)

5) Extensive Prom work.

6) Delete your A/C (depending on where you live) and Smog pump.

7) SLP 1 3/4 or Hooker 1 3/4 LT with full 3" Catback.

8) Cold air intake and clean filters.

All of this might get you around 350hp at the Crank. I think you'd need a 50 shot to get 350RWHP though. Or switch to a "RAM" and get a CC306 camshaft...

Good Luck!!!

 

My favorite head is the AFR, I run a set on my big block chevelle and they are awsome. They are also expensive to most.
Not sure if you are looking for aluminum or not, if cast iron is okay with you, I have a set of World Sportsman heads on a 406 in another car, these heads flow decent, I am happy with them, and they are not that expensive, although I run a carb on the combo, not sure what kind of issues you would run into with a TPI setup. I am sure if you ask there are plenty of people on here with that experience. Hope that helps, Larry.

 

A lot of of people think 350RWHP is a walk in the park..as easy as it sounds it WILL take some work, some cash and a good selection of parts to accomplish it. If you wanna build a healthy 350, the heads are where 70% of the power is gonna come from..do yourself a favor, if you budget is not dog thin get a set of modern good flowing aluminum castings and don't waste time and money screwing around with 20year old iron castings all to just make medicre power.

 

My budgets not dog thin, it's BABY thin...

And 300 to 350 FWHP is attainable with a decent set of ported L98's.

With his goal of 350RWHP though, that I agree would be pushing it. But I've also seen stranger things...

 

baby thin ugh chrome...I see in your sig, cute little kid man.

 

Summit sells Dart Iron Eagle heads under their name brand for about $650, guy over the Corvetteforum got a set and with no other changes says his mid range went way up on a 79 L82 shortblock.

 

B-R-O-D-I-X

 

Under $700 Vortecs with the right manifold.
Under $1100 Edelbrocks.
Under $2000 - well I'm still looking.

Jason

 

Trying to get 350RWHP with TPI is really pushing it with an A4 and 350+ cubic inches. That means around 440HP at the crank and 1.26HP per cubic inch.

I'm currently at 380HP at the crank and I'm stuggling to make 400HP with a ton of mods with very few left to go and still be streetable. Allen

 

After the heads you have to change the intake manifold.

 

Lets take a look at AFR heads again.

Last I heard there was a 2-6 month waiting list. You had to pay extra for the accesory hoes drilled, ie sensors.
If you want some good reading go over to the corvette forums and look at what those guys have to say about them, They might need a parental advisory sticker for what those guys have to say about AFR.

 

Well here how I see it I sold my aftermarket runners for $219 and my original tpi intake for just over $150 I took that money to help me buy a HSR intake for $520 with new fuel rails and adjustable regulator which is a way better intake than any moded tpi set up. Now CHP magazine took a stock 350 bottom end with alot of miles, added trick flow heads and a good streetable low duration FLAT TAPPET CAM and made 330 at the rear wheels. WITH ALOT OF PROM WORK! It was running 12.3 ETs on street drag radials.

Now if this is the power that your looking for just buy the Trick Flow 23 heads they out flow Brodix heads on the exhaust side and out flow Dart heads too. Do the research it will show you that Trick Flow heads are the closest thing too AFR and they are $300 cheaper. Use that extra money for Dyno tunning.

A TPI system will generate lots and lots of torque which is good but the secret to the HSR is it loses torque on take off which allows a stock thridgen suspension to get a better 60ft time. After 4000 rpm the HSR will walk the dog with any Moded TPI intake.

 

When you say low duration....what are the number exactly? Also, what is wrong with the AFR and what are people saying about them?

 

Not sure, someone must have had a bad experience with them and passed the word. I don't think it is anything to worry about. I use AFR heads on my 454 Chevelle and love them. They are pricey, I went with CNC porting etc.. which jacks up the price but out of the box they are still an awsome head. I know of a couple hot small blocks around here running the AFR 195's, great head with awsome flow numbers.
I can tell you the big block heads I bought flowed 370 cfm on the intake side with only a 305 cc intake runner, that is awsome if you compare other flow numbers. Brodix big block heads can flow that good for big blocks but you have to jump way up to a 345 cc intake runner which kills volocity. For such a small runner the AFR's flow incredible numbers on the big blocks.
If you watched the pump gas drags, out of the top ten finishers in the race, 5 of them had AFR heads,,,,,,,including the winner,,,,,,, that says a little something right there. Just my opinion on them, does not matter what other people say, I would still buy another set.

 

Yea, it definately does. I was wanting to buy some for my 383 HSR engine I am building. I was wanting the 180cc for the extra velocity and low end but maintaining the mid and upper end. However, I could be presuaded to go with the 195cc heads.

 

I don't think you will be disappointed. The 195's are a good choice, even the 180's flow great numbers with a ton of volocity like you said, that would make a ton of torque on a 383, a real tire killer, a blast to drive. I think either set will put a big smile on your face Take it easy, Larry.