sbc heads HELP!!!

I did a search but came up empty, hopefully someone can help. I have an '80's chevy small block 350 4 bolt, the heads are junk,(they are #462624, 76cc) but they're cracked... I do have another set of heads(#3814480, 70cc) these are from '60's 327sbc.
My question is are these chambers too small for the 350? will it make too much compression? or am I screwed?

 

It depends on what pistons you have. Dished or flat top?

 

stock pistons, standard bore

 

they really won't bump your compression too much , maybe a half point...just an estimation. your compression now may be low to start with, does it have dished pistons?

i'm sure you have already noticed the early heads have smaller valves

 

Stock as in""Stock Flat Top"" or stock as in ""Stock Dish Top"" ??? >>>>.

 

the pistons should be ok But remember the 68 and down heads dont have the abilty to mount ac due to no holes on the front of the heads

 

If they are dished pistons, your probably good and around 9:1 or so. Flat tops would put you at just over 10:1 and would require a healthy cam to bleed off some cylinder pressure to get away with premium.

 

not really sure.. not an engine guy, but they have four "c" notches like these ( )
( )
and are flat otherwise..

 

oh ya, got a "healthy" cam this week

 

you have flat top pistons

 

thanks for all the help people...

 

What's the specs on your cam?

 

comp cam CL 12-246-3
gross valve lift In. 0.487 Ex. 0.490
duration @ 0.006 In.-274 Ex.-286

 

That cam should do, just make sure your valve springs are up to it.

 

yeah got all new gear, everything from cam up

 

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I think the compression of the motors of the 80"s was probably in the 9-9.5:1 area. I see no trouble with running these heads. How early 60"s heads are they, keep in mind you want heads with all the accessorie holes there, later 60's. Good luck