Why not use the original-equipment Rochester 2-BBL? Untold millions of them were used on 283's from 1957 to the early to mid-1960's on car and truck engines. There's bound to be a bunch of them left, either as rebuildable cores or already-built replacement carbs.
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!