If you know the current HP per C.I. on the 470 use that formula and add .2 to .4 HP per C.I. for the increased compression and do the math I'm in the middle of preparing a proposal on a large C.I. B1 headed motor, I'm going to use 1.55 HP per C.I. on that estimate for pump gas with 10.5 to 1 with a single large CFM carb.on a cast B1 intake