Small Block & Big Block Chevy Specific - 76 to 64cc heads, how do I figure out CR

I am about to put on a pair of 64 CC heads, currently my CR is 8.5:1, what will the new CR be?

At the same time I am going to do a cam swap, I'm thinking about the summit cam SUM-K1105 (Duration 282/ 292, Lift .465/ .488) unless you think thats a little big, just looking for opinions on how that would work with my combo in my signature.

The change will net you a cr of 9.6:1 if all other factors remain constant.

Thanks, anyone have an opinion on the cam?

just looking at it it looks fine, but you should really get the duration at .050, not advertised (224 int./234 exh.)

New question, what would my CR be with 53 CC heads? Thanks in advance