small block fresh up

hi, the 2bbl 273 has 8.8 cr ,by cutting the deck, and the heads, can achieve 9.5 cr. the 273 heads will outflow the 302 heads in the .100 to .450 lift range.
the 273 head has a fatter flow curve. there is about 37 CFM more flow at .300 lift in the 273 head.at .500 lift, very close same. the mid lift flow curve is where the valve spends most of its time,opening and closing. the 302 head has about same shape combustion chamber as the 273 . If you want better flow, just install good sst valves. the 273 head responds very well to that change. the 302 didn't!!! i have tested both heads on a flow bench.