Hot Rod Forum banner

Compression decision

535 Views 3 Replies 2 Participants Last post by  ap72
Hi everyone,

I have a 350 that I am about to put vortec heads on. The motor has flattop pistons with 4 valve reliefs and has a stock deck height. I have the intake and all the necessary hardware for the swap. I plan on driving it as a daily driver so I want to use pump gas if I can get by. So my question is do I get the head gasket with the .041 compressed thickness or the .051 thickness. According to a compression calculator, the final ratio would be 9.96 or 9.71 respectively. Am I splitting hairs here or would one gasket give me a more desireable quench than the other? Thanks.

1 - 4 of 4 Posts
What is yoru piston to deck clearance? You may be better of going with a .018" gasket if your clearance is bad.
I'm not for sure but I would imagine around .016 since it has never been decked and with the flattop pistons. I dont have the old heads off yet, but will measure when that time comes.
YOu want the distance from the top of the piston to the bottom of the head to be .035-.040". Use the gasket that gets you there and let compression fall where it may.
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.