Way back noted racer Bill Bagshaw got 511 horse power out of a 30 over 440 with six pack pistons (heavy) at 9 or 9.5 to 1 I forget which, carefully home ported 906 heads with 2.14 1.81 valves using the MP templates and a holley street dominator intake and a holley 750 DP 4779 and 509 MP cam. Went mid 10's in a duster iirc. Dont remember if he unshrouded the valves or not (needed with 2.14/1.81's) nor what torque converter he used or fuel (he would have had no quench)