Cranking Compression

If you've got those pistons in there and there was no excessive milling on the block or heads, it's closer to 8.0:1 static compression. They are short (end up .110" down in the hole if your block is "only" 9.60 deck height) and they have a 14cc dish in them. In order to get 9.5:1 static, you'd have to have milled the block over .100", or cut the heads down a ton AND milled the block a bit. The problem is the pistons IMO. If it were me I'd be looking to go down a couple steps to the XE274H. 160 psi is ok for an iron open chamber head, but not great. And truthfully, it's low for an aluminum head combo.