Welcome to CHR!

For what you're asking, I'd stick with a good rebuilt Q-jet 750cfm like this one:

http://www.summitracing.com/parts/su...make/chevrolet

$300 with free shipping and you know it will work fine as it's the carburetor that was originally there so all the linkages, etc will fit. In my opinion, a well tuned Q-Jet is near impossible to beat - especially in stock or near stock engines.

Good luck,
Glenn