The OE Mopar carbs were small. But the factory had to contend with a lot of limiting factors. Timing curves, cam profiles, exhaust, etc all had to be less than optimum to let anybody with a driver's license to be able to floor it under almost any driving conditions.

Which is why bigger cams, hedders, re=curved distributors, al. intakes, and bigger carbs helped our Mopars.

It's not that the Mopar engineers didn't know what they were doing, it is just that they had a ton of constraints that you and I don't.

Throw the 750 on it and rock!