I have a 1250 converted to a 2 circuit and no issues. An to the contrary, the factory Holley 3 circuit Dominators (not the Ultra with billet blocks) can run lean up top, they have idle feed tubes in the mainwells that can be restrictive in some cases. The 2 circuit blocks do not have the tube nor the issues that they can create. The smaller airbleeds are there to get the metering flat without the 3rd circuit. Also, the 3 circuit Dominators tend to be excessively rich in the midrange where the intermediate becomes active. This can create issues with loading up in the burnout. For bracket racing you want the carb on the lean side driving around at part throttle to keep the plugs clean, yet be tunable to what the engine needs at full throttle. The 7320 would work fine for what you want to do.