I think the 750 is to big you should be good with a Holley 650.
How To Calculate CFM:
Engine size (CID) x maximum RPM / 3456 = CFM
CFM @ 100% volumetric efficiency
(Example: 350 CID x 6000 RPM = 2,100,000 / 3456 = 608 CFM)
and think about it you are no where near 100% volumetric...