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

Don't know, probably none. Ferds only won when the engineering faults were fixed with factory backing, money & engineers; without that they would have won a big, fat...zero.
Yep, dedicated to racing and saw the merit in it. GM did it too. Limited edition, homologated for racing models .
Chrysler could have had some good stuff, if they had bothered to try a little harder, but they were more interested in Government, fleet sales and tax breaks.
Just a better optioned V8 engine and 4 speed would have been a good start.