Upgrading stock 1971 318 heads

We have a 72 318 with stock short block and had 360 heads on it... I checked it to be 7.6 compression...

I installed a set of 67 318 heads (66 cc chambers) that I had ported and 1.88" intake and 1.60" exhaust valves installed (stock 360 valves), and with a .040" head gasket got it to 8.6 compression....