With a 650 ish,, it'll run great,, with a 750ish , it'll run awesome..
You can pick up a #3310, a 750/780 Holley at any swap meet for less than $100,, kit it, and luv it..
What you'll find is a lotta folks have fine running vehicles with a 600/650 carb,, cuz they run great,, but they've never tried a 750ish ,, so frankly can't compare,,
What you gotta do is find a buncha folks saying they took off the 750 cuz it was too ???.. and put on a smaller carb,, and there won't be many... and those folks that did,, would be looking for gas mileage, not power..
I've replaced 3 - 650s with 3310s in the last year,, and the owner's grins said it all,,
not one of them wanted the old carb put back on..