Better Performance Output

273 said
Install a vacuum gauge.
And see what your pulling at a full throttle run. Then go from there. If its higher than 1.5 you definitely want a bigger carb. Just make sure it aint the breather holding it back. If your more like 1 its debatable.

I basically agree. Even around 1.5" I'd say its a crapshoot whether there's much to be gained. Depends a bit on the quality of the fuel distribution. Up around 2" Hg at the end, I totally agree. Just make sure your throttles are fully open with the pedal at the bottom when you do the test. (forgive me if that sounds basic, but its often overlooked)

Raul said
If I went with a 750, what brand carburetor is better with throttle response? Holly, Edelbrock, or are they pretty equivalent?

Which ever one your most comfortable tuning. Honestly, I'd look for an old school Carter or Holley (pre 1990s) like a 4779 with a low - revision number. Less likely to have problems (and new carbs aren't cheap). Since you're running a Holley style now, there's the slight advantage of keeping the same fuel lines.

All that said, might want to experiment further tuning with your current setup. Working with initial timing, see if more vacuum can be developed at idle (in drive if an automatic). On the dyno, make sure the fuel curve is flat, and at the track, finalize jetting (and total timing) for best mph.