340 intake and carb combo

Firstly, in 1971 if the carb is OEM, it is either a Carter AVS or first version of the Carter TQ [ 1971 only ]. Not an AFB.
If it had an AVS originally & now has an Edel carb [ AVS or AFB ], either carb is very well made & reliable; & rebuild kits readily available.
If it is a 1971 TQ, they are hard to get parts for but you could rebuild it & use it if the internals look good. Or use a 1972 or later TQ.
Holleys & speed demons are best left on the shelf.....along side the other junk.