Some accessories like distributors, fuel pumps, and carburetors will bolt on, but no guarantee that they will work as well as the correct items. I believe starters and generators will also swap.

One trick dirt track racers used to use was to adapt a GMC oil pump to a splash-oiled Chevy engine to get better oil pressure. I'm not sure how much tinkering was involved in that swap, however.
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!