Friend gave me a holley list 4777-2 650 Double pumper-freebie. I believe the 650 & 750 share the same baseplate, so if I install a proform main body will this carb flow 750cfm or more? Are their any additional mods that have to be made? For 100 bucks may be worth it instead of looking for a 750.Btw 427 BB 10 to 1, 390 geared. Thanks

67100C--- Main Body Fits Holley Double Pumper Models 4777 (650 CFM), 4778 (700 CFM), 4779 (750 CFM), 4780 (800 CFM)

i bought one and loved it enough to buy another one for my other car .i think they are supposed to flow 830 cfms if i remember right.no other modifications they come with jets a good starting point any way and also with non stick gaskets