SBC heads, what's interchangeable?

Don't kick yourself over the fact that the 350 had 416 305 heads. This is a common and cheap way to raise the compression on a 350 with the type of pistons that yours has. The fact is you would still have to find heads and not knowing all the stuff you asked about just makes it more nerve racking and it don't help when an exchange shop sences they got someone to sell a bag of goods when all you really need is a set of out the door no exchange stock heads.

 

Please check www.chevytech.com if it will still pull up.

Best SBC head site there is even tho it's not 100 percent complete.

Now, bttt, the old '67 L-48 350SS engine has 5 cc, (or so), 4-notch flat-top pistons with a deck of right at .025" down in it as well as stock GM .020" thick steel shim headgaskets and medium valved 64 cc chambered double-hump heads, (-462's). This created right at a 10 to 1 CR'd engine even tho GM called it 10.25.

I figure that if you have -12 cc dished pistons and say regular medium valved 74 to 76 cc chambered smog heads, you are probaby right at 8 to MAYBE 8.5 to 1 CR'd with way thicker composite headgaskets.

A set of right at 69 to 70 cc heads and shims should put you up right at 9.25 to 1 or so if memory serves me right and it's been quite a while since I've ran the numbers.

The best bang for the buck is a set of flat-top el-cheapo rebuilder pistons and 60 to 64 cc medium valved heads along with shim headgaskets, imho.

I say this tongue in cheek because rebuilder pistons can be way down in the hole which really messes with your deck height/headgasket thickness/CR. so check this closely. I would examine K-B's piston site here for CR. info and go...

But this get's you into the short-block.

I wouldn't even worry about balancing it for a mild street engine unless you have a couple a "C"-notes laying around or maybe a schosh more??

And if you really want to do this right, then run the numbers and pay the money to create what you want.

And as always, jmho.

pdq67

 

Back again, I gotta come clean and say that I'm way "Old-School" and dig the old double-hump heads, but this said, the newer Vortec's kick them in the head for delivered price performance unworked over.

Just adjust cost to run them accordingly. A new Vortec style intake if they aren't drilled for the old style as well as the guided rockers and different valve cover bolt pattern here is all.

pdq67

 

All this info has helped alot, thank you guys for sharing the knowledge, I'm gonna give these heads a shot, I won't know right away how it runs because I need a few more parts but I will update asap!!