Some advice..?

Alright. Well would you say a 750 would be good? Some say it is way too much carb.

Gears are ordered. Next is....a carb?

750 CFM is right between what you need ofr your engine in NA form and what you will need for a blow through. Slightly too much for NA and too small for major blow through.

Ok cool.
I kinda feel the 600 being too small. Once you get up in the RPMs it feels okay, but can see where it would improve it.