Overlooking something? Fuel Starvation
Get you one of these Holleys.
0-80528 750 Mechanical secondaries (Manual transmission)
0-80529 750 Vacuum secondaries (Automatic transmission)
Or you could rebuild the 3310 you have and send it to BJR Racing. He has a trick for the 3310 carb that I'm not sure of all the details but you have to buy a metering block for the secondaries and let him do the rest. He is a member of FABO. He has spoke to me about this and it sounds it will make a car run like a scalded chicken.