How much trouble would it be to go back to a one carb setup? With your other improvements over stock, if you go to a single carburetor, I bet that all of your woes will disappear, your gas mileage will improve, and your performance will not suffer one bit.
With your 2.73 rear end gears, you will never reach high enough RPM to ever utilize the supposed benefit of having 2 carburetors, in my humble opinion. (I can be humble if I try real hard.)
Carl
