305 heads

[bill179]

what is the combustion chamber cc on 1987 305 TPI cylinder heads?
any other information on these heads would also be useful and appreciated.

[swollen balls]

55-58 cc's
nice heads to put on a 350

[89IROC&RS]

i think they are actually 58cc, however, they suck. small valves, poor airflow, shitty chamber. all around poor head. better head is world products 305 torqer heads. or use vortec heads, with .015in copper shim gaskets.

[4onFloor]

ya, there not the best heads. but if your on a tight budget like i am, there a good head to use on a 350. they'll raise your compression, since i think 350 heads are 64cc

[89IROC&RS]

vortec heads are 61cc, and with the copper shim gaskets, will proby give you more compression than the stock setup, havent crushed the numbers on that one. so yeah, if you just bolt the 305 heads on a 350 it will raise the compression, but definately do the math, you could wind up with like an 11:1 compression. no good for street. and as far as budget, youd probly be able to get the vortecs for close to the same price, find a wrecked 96-99 tahoe, silverado, suburban, or GMC equivilent, with an R code V8, and you got em. just a pair of Iron heads as far as the junkyard is concerned. no different than the 305 heads. but if you go after the vortecs, be sure to get a pair, with the casting number ending in 062, not 908.

[4onFloor]

what i did was, i bought a wrecked 1990 camaro RS/305, for $175, i pulled the engine and tranny and a few other things. i'm using the 1990 heads on my 71 350, i'm using the throttle body and wiring harness to run fuel injection in my 71. not a bad price for the heads and all the stuff i got, and it only cost me $18 and a little time to rebuild the heads, i also did a port and pollish job.

[89IROC&RS]

not a bad use for the parts, pretty inventive actually. me likey, but still, the vortecs are just as cheap, and flow nearly as much as bowtie heads, unported. i scored a complete R code 350 for 100 bucks, only thing wrong was it had collapsed lifters, and the bearings were starting to go, thanx to an internal coolant leak. but everything else was fine.

[4onFloor]

i'm not too familiar with Vortec's. I tend to stick with what i know works, and toy around when it doesn't cost me money. I'm sure it's a better engine, or they wouldn't have slapped a different name on it.

[89IROC&RS]

lol good point but i have yet to see a 350 with those heads, run less than 400hp. that is in hot rod and such. thats proof enough for me. not to mention i have seen the flow numbers, and the possiblities for improovement. heads are amazing. thats why i just cant let em go, i love em i love em i love em

[bill179]

my friend is building the engine for as cheap as possible and wants alot of compression and i told him to find vortec heads in a junkyard but he didnt seem interested even though the manifold he wants fits vortec heads.


but i agree that vortec heads are the way to go

[4onFloor]

get your smaller cc heads, and combine those with a set of flat tops. that should raise the compression

[89IROC&RS]

your friend is more interested in 305 heads than vortecs???? not to be a dick, but he needs to go back to school. that or he is wayyyy to focused on the chamber size. there are many many other aspects that go into a good head, and making power, than the chamber size. a set of flat top pistons, shim gasket and vortec heads will give you 12.5:1 easy out of a 350. and like i said, you can get the vortecs for the same ammount as the 305 heads. ah well, thats my advice, if he really wants to get the 305 heads, let him. hes just making a mistake in my opinion.

[bill179]

hes got the heads now they were on the engine when he took it out of the car and i think he has flat top pistons to put in the new engine already
oh well ill talk to him tomorrow

[4onFloor]

what year and what size of block is he putting these 87 heads on?

[comp]

if you use a 305(small bore) you help air flow by "relieving" the top of
the bore back just before thehead gasket line. don't go down to top of
compression ring travel i n bore