I already have the heads I'm going to use. The heads I have are #197. I wasn't after the big ports and valves but I was after the 111cc combustion chambers ( mine are now 114cc ) My research says these heads are off of a 1971 Ram Air IV 455
http://www.firebirdnest.com/index.php/15-2ndgen/transam/4-1971transamThis motor, with these heads was 8.4 to 1 I think the stock piston was a 34cc dish. My pistons, flat tops with four valve reliefs should give me around 9 or 9 1/2 to 1. I haven't done the math or checked the piston/deck yet. I don't think compression ratio will be a problem. But, something else...yeah maybe