80’s 318 compression ratio figuring out where I’m at.

Upon closer inspection the pistons are 0.030 over after I cleaned up some more carbon off the top. I cc’d the head and looks like it’s been milled already? Came up with 63cc chamber. I’d like to swap pistons, but that requires a whole tear down and rebalancing, which I don’t want to do for this “play” engine. I’ve got 3.23’s in my 8.25 rear. I have a set of 3.73’s I’m gonna swap in this summer for some pep. It’s a 4 speed. My new revised calc with 6cc valve reliefs and 63 cc chambers and 30 overbore is still crappy 7.6:1. If I get a 0.030 gasket (O.20 thinner than what was there), and mill the heads another 0.40) I should get to 8.6:1. Good enough? Worth while?