I've got a 1984 Pontiac T/A with a 383 stroker, Edelbrock performer rpm dual plane manifold, 1in phenolic spacer, Holley 650cfm DP carb, 1970 400 heads,auto th700r4 with shift kit, with a posi 3.73 rear. Does anyone know if my heads are any good for the car or if I should invest in some new heads that'll make better power? I cant find any specs on them except that they are from a 1970 400 engine and have 76cc chambers.

idk much about old heads but most stock sbc heads are complete garbage

if you want to make any kind of power from that 383, dump those '70 400 heads...they would be a serious bottle neck on that motor

What kind of heads do you guys recommend? I was looking at a nice pair of Dart heads and then to have them ported, but maybe some AFR heads would be better idk. Any suggestions?

Check out the aftermarket "vortec" heads from RHS and EngineQuest.

EQ Cylinder Heads Home Page
Racing Head Service - RHS™ Performance Cylinder Heads - Home Page

What is the casting number (under valve cover) on your "400 heads"

Vortec heads with a custom port are probably the best bang for the buck. They perform close to if not better than some aftermarket heads. Your heads now are probably bogging you down bigtime, not only because they probably flow poorly, but also because you are probably at an 8.5:1 compression ratio. The combustion chamber size on those heads would be more suited for a forced induction application.

So there's vortecs, or, if you don't want big heavy hulking heads, you could go for cheap aluminums from Brodix, Summit, or Trickflow for just under $1000. I really think that those heads would open up that motor for you, but you won't see the full effect until you match it with a nice cam. No matter what option you do, take the time to get a nice port job done...you can't do them once they are on the car, so I always say go for it.

vortecs are the way to go, hands down. but they are not cheap. another option would be a set of double hump heads. they were made before all the smog regulation b.s. came about. the double humps are a bit cheaper but dont create as much power. as for the cc's on the heads, anything over about 68cc is not worth a thing. if you're interested i have a set of reworked 291 casting double hump heads that came off of a 327 out of a '67 camaro. now i know the motor is smaller than your 383 but from what i understand it doesnt matter. a small block is a small block and externally anything for a small block will work on them. if you do decide to go w/ the vortec's everything ive read says that the vortecs will give you anywhere from a 25-40 hp gain over stock heads. personally if you have the money an extra hundred bucks or so it is worth it for the power gain.

They were never made for performance, just like the 262 and 267 engines were made to haul your grandma to the grocery store. Cheapest option is a set of cast iron aftermarket heads; 195 cc runners with 2.02/1.6 valves:

They are cheaper but heavier. Your comp ratio shouldnt be much more than 9.5:1, as the higher specific heat of iron causes more heat to be retained in the combustion event and the engine is more detonation prone than with identical alum heads

Aluminum heads can run about 1 point compression higher than iron heads all else being equal. One caveat is that the same thing that makes alum heads able to run higher comp is that also causes a slight power loss due to the increased amount of heat being transfered away from the chamber.

While you are at it 1.6 roller rockers are a good addition. 10-15 hp from friction reduction, and more top from the increased lift without much effect on bottom end

Well I say if you got the money get the AFR heads! Hands DOWN they will kick the crap out of any other head on the market thats not CNC ported. AFR comes ported already. You can go with Vortecs they are some good heads but the power that can be made with AFRs on your 383 compared to Vortecs is no comparison. DO IT RIGHT THE FIRST TIME! AFR just release their Eliminator heads in CHP magazine those heads made 523hp on a 388 sbc 10.6.1 compression, 850 carb with a XE284H Flat Tappet Cam!

I have a set of Competition Ported AFR heads I bought off a guy an he dynoed 505hp on his 9.5.1 comp 383 with a lunati flat tappet cam that only had .515 lift. My point is your not going to do that with vortec heads without some serious work and that kind of port work cost over $1000. Just do a search on yahoo or google and see all the different sbc combos there are with dyno results you'll see.

The 210cc fastburn heads still seem to work fine and can make decent power for less. They are a 500+ hp capable head. Even the bowtie vortecs are capable of that power.

Dart sportsman 2's are good choice also.

Okay, once again the myth is mightier than the truth. Double hump heads are 30 year old technology. They are crap when compared to a modern cylinder head. Don't even waste your time with them a stock set of Vortec's makes them look pathetic.

If you want to go with ported heads I rec. just buy the base model as cast and having a reputable machine shop port them and install springs. Trick flow's bottom line 195cc heads are a good starting point. http://http://store.summitracing.com/partdetail.asp?part=TFS-30400001
They don't flow as much as ported afr's, but for about $400-500 of machine work your heads will be set up for your comp. ratio, cam dur. and lift, operating rpm, intake, etc. The more the machine shop asks you about your setup the better. I'm not sold on factory ported heads because of the amount of variables in a motor

I totally agree. Even CNC'ed heads willl need work to get them to perform best for any given application. CNC is generally to get the bulk of the porting out of the way so only minor work needs to be done.

New. - Old castings(especially 70's era smog crunch, as yours) leave much to be desired. Poor runner design/flow, poor chamber design/efficiency, you name it, they suck. The vortecs are the only decent factory cast head. The old double hump/fuelie heads are still really out-date technology, and fully worked still won't make the power a set of mildly ported vortecs will.

If you can stomach the $, then buy some RHS, AFR, Canfield, Trickflow, Brodix, Dart, etc aftermarket aluminum heads. The technology in these heads surpasses anything GM ever produced by more than you could ever imagine. Then get a decent cam to match your combo(ci, gearing, heads, etc)

Always remember this, The top-end makes your HP, you just build the bottom-end to stay together. - Meaning you don't want to get your azz kicked by some guy's 305 with decent heads.....

The casting number on the heads is 3951598. Thanks for all the info I will be buying some aluminum aftermarket heads either AFR, Dart or Brodix heads. These heads dont seem to flow that bad but I guess some high performance ones will be much better for my car.

They're cheap around here. 300 bucks for set fully assembled. Sometimes cheaper. The 062 and 906 castings. We're talking about the same heads right?

Vortecs are often considered expensive because they won't simply "bolt on". You also have to change the intake, or have the knowledge/ability to modify the heads to accept the standard intake bolt pattern, plus raise the intake to the vortec port height. - Also, stock vortecs will only go to .470 lift. Any more and you have to have the guides and pockets machined for different springs and for clearance.

i have a 87 iroc with teh 5.7L and i bought a pair of edlebrock e-tech headers and had them sent to jet hot and was wandering how much they will help and if it was the right way to go for teh money, because i only spent 225 for edlebrock headers, y-pipe, and cat converter. i was also wandering what type of spark plug and wires to get it is stock except fot headers and computer chip

Did you even read this thread before you posted?

Anyway get the AFR heads it will make that 383 scream! Then you'll be back on the forum asking how to keep the car in one lane!

Well I guess now is a good time to start my AFR heads fund. I should have them in a couple of weeks but I wont be able to find out how good they perform until the spring due to it being like 40* and gonna be snowing soon but I guess I'll be able to tell a little bit once I start it and hear the diffrence. Again thanks for all the help everyone.

If you want the cutting edge a company called ALL PRO makes heads that blow away AFRs. I was talking to a dyno shop guy who has tested just about every head and they said the ALL PROS blow everything else away.

Any hard numbers?

Do see on there website they have aluminum 305 heads, kind of different.

I wish I did but really all I can go on is what a dyno shop had to say. I cant say if its bull or not but it looks interesting.

Cold air makes more power go ahead and see what she can do.

Does All Pro make the Top Line or is it pro line brand of heads?

From what I understand All Pro is entirely their own design. They take from Nascar designs if you look in the catalog. Its not cheap stuff though. I have never seen another company offer various stages of cnc porting either.
http://www.allproheads.com/

All pro are the top of the line for sbc. and it will be reflected in the price tag.Afr has great heads as well as Dart the Brodix seem to work better with port work.

Would I be able to bolt up vortec heads to my intake manifold its a Edelbrock performer rpm manifold? If not then I'll be looking for the best set of heads that can bolt right up to my intake. I do have the edelbrock performer rpm cam if that makes a diffrence in anyone opinion to what I should get, maybe I should just go with the performer rpm heads?

I have a 89 Chevy truck 4x4 with vortec power and TPI by Edelbrock. Looking to build another 350 for it and am committed to the vortec style top end, besides the Etec's and AFR's is there any other aluminum heads out there that will substantially outperform the L31 head and make torque to move 6000lbs? Looking at http://www.chevyhiperformance.com/te...tec_head_test/
The etec's aren't decisive and I don't want to move into 200cc territory.

Vortecs will not bolt up to a standard sbc intake unless you have the know how to properly drill and tap the heads for the standard bolt pattern and run a thick gasket to accomidate the taller ports. - That said, you're talking about spending over $500 difference just to stick with the same $100 intake? Don't get me wrong, AFR/RHS/Trickflow will make more power with the proper cam, but the intake change alone is no justification.

Stick with the vortecs. For the best of the best, try finding a set of the Topline vortecs, they're better designed and better cast than GM factory. So far Comp/RHS hasn't re-upped the model, so since the buy out, no new ones have been available. - Stock or aftermarket, just do some clean-up porting. Take the ridge out of the bowls and smooth the transition points. They're great heads for power and efficiency. The 4x4 Tahoe I built is a 350 with mildly ported vortec heads, an 87 MAF TPI, the GMPP/Merc Marine hyd roller, a 700r4, 3.73 and 33" tires. It'll out run many sports cars, knock down 18+ mpg doing it, and it tows the 28' inclosed trailer with the race car/tools/4 wheeler 80mph right on down the highway, still getting 15 mpg.

Well since vortecs are outta the question, I want a set of heads to match my cam and intake. They are the edelbrock performer rpm cam and intake. Would a set of the new AFR eliminator heads be good. I am willing to spend a lot of money to have the nicest heads.What do you guys recommend now?

If you got the money to spend AFR heads would be a great choice, just a matter of picking the right port size and combustion chamber volume.

So far there doesn't seem to be alot of first hand user experiance out there for the 170 Etec's or RHS performance vortec (the 200 Etec numbers look great but my engine wouldn't be able to use them). I am a little leary about the 'dual' intake bolt patterns because it usaully isn't spelled out clearly that the heads are a direct vortec replacement with proper raised port configuration and not a compromise between the old and new port dimensions, I don't mind clean up- but full on porting on new heads is a no-go. I think the AFR are more at home in a buzzy Camaro than in a truck and there may be other choices, anybody heard of Brodix vortec's? I plan on using Mahle pistons and as I read it they won't give me more than 9:1 with a 64cc chamber, other wise I was looking at 9.5-10:1 with aluminum heads to be able to retain use of 87 octane. My experiance so far was when it came to rebuilding a set of fire damaged GM vortecs with ss Manley valves, Comp springs and all the goodies- I could have got the Etecs for very little more- so no more rebuilding for me.

I've got a set of the Topline (now RHS) vortecs under the bench. They're much better cast than GM. Plus they're thicker in all the right places to allow for more porting and less tendancy to crack.

The Topline/RHS vortec heads are decent heads. I know someone with a 3200lb car 355 and 3.73 gears running at 11.89 @ 111.30 with those vortecs and no porting. He just tossed them on with stock rockers and all at the beginning of the summer. He paid a whopping $500 for a complete assembled pair.

For the RHS vortec is there any reason NOT to go for their 2.02/1.6 version?

The heads that made the numbers I posted had the 2.02/1.6 valves.

Interesting, so cast iron is definitely still cutting edge in the world of 'street' heads. Would I be right in saying that someone wanting to upgrade but still retain 100% factory specs would buy the RHS 1.94/1.5, and someone wanting the vortec compatability but a step up in power would pick the 2.02/1.6. I read somewhere that OEM vortec's really don't respond as well (as other stock heads) to bigger valves because they are so optimized for the 1.94/1.5- so a properly 'engineered' vortec with 2.02/1.6 from RHS should be a worthwhile purchase.

ok so heres another thought. what do you guys think would be the best for a 350 with flat top pistons, a current edelbrock performer plus cam. (daily driver) the aluminum gm vortec fast burns, edelbrock etecs, or the trick flow 195cc 23 degree heads. the reason i have chosen these three is because afr heads would require lt headers, and i havent heard a whole lot on the etecs and the gm fast burns. i have compared the flow bench results from the e tec heads and the trick flows. the trick flows out flow the etec but would the combustion chamber design have a power output difference over the trick flow heads. i know they are all good heads but what are your guy's inputs on this?

The power gained from the topline/RHS vortec is not just in the larger valves size, but in a much better/cleaner as-cast head. No giant lip in the bowl, smoother port to bowl entry/exit, just a better design and better cast head than the factory GM units.
The AFR's don't require LT headers. BUT, just like the rest, they will benefit more with lt headers. - I have seen/heard of several 450+hp cars running the vortec style heads, be it ported factory, RHS, Fastburn, or e-tec. - Gm makes 425hp with the fastburns on a warrantied crate motor with a weenie cam.....

do you have a part number for the afr heads and headers that will fit a third gen? i would prefer to put the afr heads than vortec but i am very open to all ideas. if i go vortec i would like to use the edelbrock e tecs or the gm fastburn vortecs. which of those would yall prefer. any pros and cons. last time i looked the afr heads have the square port exhaust, and i could'nt find anyone who made shorty headers with that port shape.

1-3/4" standard round tube headers will do the trick. Hell, my toplines are square exhaust ports and I was running 1-5/8 standard round headers. - The perfect shapped header for the ports will have little effect on the power, all that matters is that you run the proper size headers for the engine. I was very pleased with the 1-5/8 headman lt's on my car. I might have gained a little up top with the 1-3/4, but at the cost of some bottom-end power curve. The trade off just wasn't there.

i have the 1 5/8 hedman shotrys on my car now, they will cover and work on the afr heads with a 1.5 x 1.5 square exhaust?

They'll work fine. You might see a very slight gain from a perfectly matched header, but it'll be very slight and probably only noticeable on an engine dyno.

THEN THATS WHAT I'LL PROBLY DO. I LIKE THE AFR 180 STREET HEADS. I WOULD PERSONALLY RATHER USE THE OLDER STYLE HEAD THAN A VORTEC. JUST TO KEEP IT OLD SCHOOL BUT, I'M NOT TURNING DOWN POWER EITHER. I'VE STILL GOT A LITTLE SAVING TO DO. BUT I WILL POST PICS OF THE INSTALLATION AND OUTCOME WHENEVER I GET A SET OF HEADS. I APPRECIATE ALL YOUR COMMENTS AND ADVICE, JUSITN

Well, priced out the RHS vortecs in 'mild street' trim and the Etec 170, difference is $12 more per head for the Etec, if the iron was substantially cheaper like I expected the choice would have been made.

The RHS vortecs are going for around $220 per head, where you finding Etecs for $12 more per head?

I'll have to reconfirm that number, but this is Canada and with different distributers pushing one brand over the other and possibly over pricing a brand and our dollar difference sometimes the pricing is wierd, the fact is- even though 'you' may get a ripping deal on the RHS heads they may cost me $500 per head. So the RHS is a good head for the price but if it works out to be very close, are the Etecs the way to go?

if the $ is close, I would almost always go aluminum....The only time I wouldn't is for a daily non-performance app.

Star performance has the RHS's for $219 - not sure if you can get it through them up there or not

Could you expand on your comment about not going aluminum for a non perfomance daily driver, there's plenty of factory aluminum out there? Mine is a daily driver with decent power but definitely looking in a different direction for torque than most guys at thirdgen. The truck is well maintained including coolant changes at the appropriate intervals, already has an aluminum Edelbrock Hi Flow Vortec intake so other than electrolisis whats your issues?