Anyone run a Street Avenger?

If you want consistent idle, open the heat crossover. Just that simple. In Canada, a choke would be perfectly reasonable as well.

As for performance any 750 CFM carb providing the correct mixture will provide the same power as any other 750 CFM carb providing the same mixture. The AFB/AVS advantage on the street is you can richen/lean the power and cruise curves independently. On a Holley pattern carb you transpose the power/cruise curves paralell and together via a main jet change. That is, more power circuit fuel = less mileage when you increase main jet size. You can increase the bias distance between the two curves, but this involves drilling PVCR channels and is neither a simple nor reversible task.

Your combo is not too far removed from stock, and certainly within the realm of an off-the-shelf carb. Personally, I'd run an AVS (Chrysler did).

Really though, open the crossover eh. And see if that helps.