I know a guy with the ZZZ crate engine, its identical to yours. He used a 3310 holley 750 VS carb. I know they are rated at 345hp but dont know how correct that is. Its got a nice idle and has really good power. In his 64 Vette with a th400, 2500-2800 stall, 3.70 gears and 235/60/15 Dunlops he has run 13.60`s spinning pretty good.