My NA 327 made 447 HP @ 6600 RPM. 11.1 compression, 461 fuelie heads, 2.020/1.60 valves, small journal GM rods, ARP bolts, Isky 480/480/240/240/108 solid lifter cam, 1.5 Scorpion rockers, Performer RPM intake, 750 Holley, locked HEI dist, Moroso oil pan. Ran 12.00 in less than ideal conditions in my 1979 C-10 long bed truck.