650 or 750 cfm. carb??

800's-930cfm, good mention, and it really depends on the tune and transition circuit on weather it'll work 'better' or not.

If you tune for, the bigger carb will make more power before 6000 rpm at any point from full advance. jmo

A bigger carb will not make more power if the engine can't use the capacity the carb has and a 360 turning no more than 6000 rpm just can't use all the capacity of a 750. You can certainly can tune the carb so it will run but you will give up throttle response compared to a smaller carb.