I would see if the motor will even run at a low enough idle speed with all that bypass air before I went to too much trouble. Just vent the vacuum port you plan on using and see if Idle is still doable. This could also cause fuel distribution problems at wot so be careful. Time might be better spent optimizing the rochester 2bbl. that you have or finding one that is better. We work with those 2bbl carbs on the dyno alot and sometimes find big differences in power between carbs or by fixing problems in the carb you already have. A mopar with a rochester 2bbl racing circle track is a rare breed.
