Hey guys there is a guy locally selling a seto of 70s corvette double hump heads, he says they will really wake up my 305... I am running the stock cam and heads on my LO3 right now, I have intake and header/dual 2.25in exhaust.

Would i be able to put the heads on in the car and could I use my stock cam pushrods and lifters or will I have to buy new ones. I am assuming the heads come with valves and springs and no more.

I assume I will need a plethora of gaskets and such, But if I am pulling the motor out of the car how hard would it be to put rings and bearings in it?

Thanks for all of the help in advance I know very little.

 

That's a terrible idea. Never trust the 'recommendations' of a guy trying to sell you his stuff.
Do not use those heads, bad choice on your engine.

 

 

Sweet Thanks guys.

 

hey trey the worst thing in the world is for you to listen to other peoples opinion because they dont like something , im running a 355 kb flats .elgin solid cam ,eb rpm performer intake ,750 eb carb ,accel dist.and one very old set of 1968 461 camel hump with 1.94 intakes ,listen aftermarket heads are great if you can afford them but if not go with the double humps mine works flawlessly and if you didnt know better youd think it was a roller set up if you are just starting these heads would be fine considering he wants a reasonable price for them just remember that they like a lot of advance the only downfall you have now is the small bore 305 but work with what you have for now until you get a 350 ,these heads also love a small hit of nitrous i run a 150 shot hitman by nitrous express 3.73 gears with the rear weldedl up and this thing moves and loves to rpm with these old heads ,however make sure you check for coil bind and you may need to shim them a bit ,also be mindful of the compression ratio with some of these heads comb chambers could be small mine will only run on 93 octane with timing set at 32 degrees so if these heads are all that you have or can get for now i say go for it you will be surprised bigzeke355 bird
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oh and yes they will bolt right up to the 305 and you can use the same pushrods and lifters ,however i would buy new lifters and pushrods but what im saying is yours are interchangable bigzeke355 92bird

 

Sure, use them if you want to have no compression ratio when you're done.

 

What casting number? Could be good (early 70s) or could be bad (not early 70s).

 

its not a matter of "not liking," but it is the finer details which would kill the performance (drop in compression).

as madmax pointed out, you would take a HUGE compression ratio hit and probably lose power over the stockers.

if you dont have the $$$ for aftermarket heads, do a DYI port and polish on the heads you have, there are several threads on here about it and some have had great results.

 

Not very effective on TBI heads.

 

461's are 64cc heads. I don't think a "drop in compression" would be a problem. GM did make some decent heads prior to the mid 70s.

 

Will I even be able to use my sepintine belt assembly with these heads? I think for 300$ its a great deal. What code do i want to look for on these heads? Like i know people always say "o they are 081s or 221s ETC (made up numkbers).

I am considering porting my stock heads but its a mess and I want to do this in a saturday.

 

you will not lose compression if if you have the correct piston block has been decked etc. dont waste your tiome porting tbi heads ,port the dhumps ,get msd ,tune the dam thing and have fun and but beware of these cats telling you youll have a drop in compression ,they probably have got a honda or something in their garage good luck bigbigbigzeke american muscle 92 pontiac firebird 355 smallblock dhumps will only run on 93 ----------later

 

I think that this is a terrible idea. I believe that stock combustion chambers on a 305 TPI, don't know about LO3, is 58cc. Like others have said, these 70 cc heads will drastically lower your compression ratio. Decking the block and replacing pistons is most definitely something that is going to cost more than $300. 305TPI heads or the corvette aluminum TPI heads will work much better. Also one of the downfalls of the LO3 is its peanut cam. If I were you, I would consider upgrading that, and either doing a port work to your 305 heads, or finding a set of good 305TPI heads for cheap and using them, over the heads that you are considering.

 

oh boy... who opened the door for the peanut gallery here?

 

Wasn't aware there was one.

 

Saculia The lo3 heads are 58cc aswell.

I agree these heads are not good for you motor as for why thats easy you have a 305 they would be great on a 350 but not on a 305 yes compression ratio will suffer especcially since you will not be having the block decked($$$) you wil need a thicker head gasket to forgive block warp an will lose even more compression when you do that. oh and you will need to use 350 gaskets on those heads too.
If I were you I would get some TPI heads. The flow just as good or better then those "Camel Hump" Heads without the CR lose. I have an LO3 as well and I converted it to TPI I just picked up a set of 081 TPI heads for $30 on this sight with a clean up and rebuild with me porting them myself I will have $350 in to them total. Machine work new vavles and springs and the porting kit. I don't think you could beat that kind of upgrade for the cost plus when i Get a 350 I will be able to swap them right over without a problem. My CR will be around 10.5 or 11 to 1. So it will be 93 only

Bigzeke. I'm not knockin those heads and don't think anyone else is either I've used them in the past on 350's but with the small bore of the 305 you just can't take advantage of heads like that

 

I just got a 89 fire bird 305 tpi motor today. if anyone wants the heads let me know and make a offer. i also have the roller lifters and spider tray or whatever its called and all that stuff also.really need to get rid of these also so i can get my car on the road

 

With those early 70s heads you won't be able to use your serpentine belt setup.

 

62cc, actually. The lack of accessory holes most likely would be a problem.

There is a difference between "decent", "good", and "worthwhile". Most anything factory production would be eclipsed by a set of Vortecs.