Carb CFM.. Increase?

Yea.. apparently there is.. It's a whole different way of thinking about it.
Your gettin it! Call up a few of the higher end carb places and give them your information and ask a question or two.
You can simply get a basic Holley or Edelbrock and say, that 750/800 will do and it will or grab something different.

A lot depends on what your doing and of course, how thick your wallet is. Is it worth the expense?
All your call.