Thanks guys for all the input! Out of curiosity I pulled a valve cover and the heads have the date code 9K25 and a cast 4 (no dot) which according to a spreadsheet I found online makes them the 11:1 closed chamber type. Not sure if that's good or not
At first I had my heart set on a 427 but now I'm not so sure, maybe a hopped up Cleveland? Yesterday I took the car for a spin and for the first time wound her up past 6K rpm and wow, that car hauls azz and with from what I can tell it seems a stock motor.