This was 91 octane 439" LG port commando motor for MP Engine contest 3 years ago. Made 613 HP @ 6500RPM at Superflow, dunno what peak would have been they only turned them to 6500 max. This is now in a '71 Dart in California.
4.125" offset ground MP crank Chevy H beams Chevy Mahle pistons 11.7:1 off shelf 266 @ .050" Crane roller Edelbrock victor LG port commando's 850 Mighty Demon