The MOPAR power myth?

Found that out myself with a 7 1/4 I was 16 and my dad let me build a 440, just stock, 906 heads 2.02 intake valves, torker 2, hooker castler headers 2" prim. Yeah that rear end did t last long behind that lol so we went to the junk yard around here she you still can find these cars and found a 8 3/4 open diff. But didn't have any problems after that.