Best carburetor and intake manifold for a 273?

welcome. i'm a neighbor in MO. yep... I have a small herd of early A bodies, but my main car right now is a 67 Bel 1 a post car, like your coronet. mine came with a slant! ha
like just said, that car and the 273 , somewhat heavy for that engine. but great motor and cruiser. the 4 bbl will wake it up some. looks like nice platform for whatever direction you go. like said, keep your eyes out for 440 motor home engine, or even a 400. if worth the $. stock they lack compression, but can be work up stock with some good gears. and a great foundation when you have or want to put $ in it.