[njsteve]

With the 6X-4 heads off a 350, around 9.5 to 9.75 to 1. They are the 93 cc heads but have been cleaned up to get them flat. The block will be surfaced flat as well. So it should make them a wee bit smaller. I will CC the heads once I get them off the 350 in the car now where they currently have 7.5 to 1 compression. (BTW, the 6x-8 heads off of a 400 are 100 cc)

Here is the chart info from the pistons

Pontiac 455 L2359NF

72cc = 11.5 1 to 1

87cc = 10.01 to 1

96cc = 9.3 to 1

111cc = 8.34 to 1

114cc = 8.17 to 1