stock pistons were dished right in a 1980 350? cause i pulled the heads and i now have flat tops that and .30 oversize

and what was stock compression ratio for a 350 and what would it be with .30 over flat tops approx.?

it was 8.2:1 stock with 76cc chambers. the guy at the machine shop told me that i would be at 9.6:1 with flat tops, .030 over and 64cc chambers.

wow that sounds good thanks for the info.

Stock 350 pistons were approximately -12cc dish back then. Low 8s for compression with 76cc heads.

Flattops and 64cc heads will get you up in the upper 9s.

Flattops (30-over) and 76cc heads will get you not quite 9:1

So how about stock dished pistons with 64cc Chambers....compresion say 8.75 to 9.0? L.P.

Right around 9, maybe just a smidge higher.