Help with identifying engine

Getting ready to order some parts now (Mancini seems to have some great gasket kits, thanks for the tip!), but I´m a little unsure about what to do with the carb..
Should I try to find an original 4973, or get another?
Been reading that it doesnt perfom that great, and that they were recalled in 1972?
Should I get a later one, or another brand altogether?

Since it´s not the original engine for the car (273 original) I´m not doing a 100% rebuild.