I've got a 75 model 500 engine and Turbo 400 trans that's scheduled to go into my 59 Carryall. There's a growing list of high performance parts for the 429/472/500 series engines, and they're all only slightly heavier than the small block Chevy engines. They have the same bellhousing pattern as Buick, Olds, and Pontiac, too! These are really great engines, and they're relatively plentiful and inexpensive.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!