Power advantage between Ford 351, Mopar 340 and Chevy 350??

In stock form, obviously you can look up the numbers from tests back in the day. None of us really give a **** about stock form numbers.

If you were to build an all out (factory iron block and heads) engine TODAY, the Cleveland 4V would destroy the Chevy and Mopar. The heads flowed enough with zero port work, to support 500+ HP with no port work. The very best "J headed" LA wouldn't come close.