Hey all
Ive got a nice amount of money to burn and want my engine performing at its best. My current heads are 093 76CC 1.94/1.50 jobbers, nothing really wrong with them except one of the valves has chipped tip and is killing the rocker. Im going to be pulling them anyway, and was looking at rebuilt 76CC gm head s or 72 CC torquers and iron eagles. I need to keep compression low, so 72CC is the smallest I can get...

Engine specs are
355
stock bottom end
rajay 301E turbo, 7 PSI boost
750 holley
crower 00230 cam 262/270, 214/224, .450/.470
3" single exhaust
procomp billet dizzy and MSD super conductors
Mallory 685 box w/ boost retard

Behind it is a 4 speed and a 3.42 open rear.

Is it worth upgrading the heads? I dont have enough for aluminum heads.

not sure,, one would think that more flow should equal more effective compression ratio at the tq peak and hp peak,, at the same boost level. or would the higher leak through trapped into the cylinders or untrapped and blown through cause lower boost numbers? hummm.... good question. maybe you'll get a good answer.

i'd wager to say that if the turbo is big enough to pump more than the engine can take and it's hitting the wastegate now at 7psi,, that it would potentially do the same with better flowing heads.

i guess there's the math that says where the turbo size to cu in size to rpm peak to cam specs(and lobe separation angles),, where it can't keep up and boost would come down,, with more head flow. but i'm not that far into turbos knowing that math. just logic says that to me. maybe more input from someone more knowledgeable. but better flowing heads can also create more blowthrough during camshaft overlap as well. don't know if it helps,, but my thoughts anyway.

stuff i've came across says with blown/forced induction apps that you want a heads' exhaust to intake ratio of more like 80%-90% of the intake compared to 70%-80% with naturally aspirated engines. maybe search on that to see what you come up with. hope it helps.

Good heads always help. You can make more power with same boost or same power with less boost. Factory heads are pretty lousy compared to what's in the aftermarket these days. If you can swing the cost I think better heads are a good HP/Dollar investment, especially since you can use them over and over on different motors later.

Since its a boosted motor, the intake port volume doesnt really matter does it? My system has an internal boost valve, so even if the heads flow better the turbo is just going to keep pushing more air until it hits 7 pounds and it regulates. I would think that better combustion chamber designs would be the biggest benefit of new heads, along with better exhaust flow for turbo spool.
Heres the heads im looking at

Dart Iron eagle $230 each bare
165CC intake runner (I can port them)
65CC exhaust runner
72CC heart shaped combustion chamber
Bronze guides

S/R Torquer $250 each bare
171CC intake runner
76CC chambers
iron guides

Both use the 1.94/1.50 valves.

Just adding my two cents, though it's not worth that much:
You will probably want to upgrade the exhaust side of either of those heads to make the exhaust flow better. Your intake will probably be fine as they are.
The combustion chamber design makes more of a difference with proper piston design-what have you got for pistons? If they are flat tops or d-dish then the heart-shaped chambers are a good choice, but if they are dished I don't think it'll really matter.

They are stock pistons. How bout I just replace that 1 valve and port the exhaust on my existing heads?