9:1.
A good 454 will have at least 150 PSI per cylinder.
7.9 to 1
8.5 to 1 compression is factory stock.
10.5-1
Compression ratio on a 1974 Chevy 350 in a Nova was 8.5:1.
8.3:1 is stock
The compression ratio of a 350 Chevy engine usually ranges from 8.0 and 9.0 to 1. This provides a good balance of fuel economy and power.
with higher compression pistons
YES. That is a direct bolt on with no problems. The heads will bolt on, but the compression ratio will be different. Depending on which heads and which pistons, the compression ratio could be a lot different.
Need to know what size engine it has to answer correctly.
6 to 8 degrees advanced. for stock compression ratio.