Plus you didn't say weather or Not the carb is New or a used one? If used has it been rebuilt?
And are you laying the pedal right to the floor when Taking off ? This to will make a Bog if the secondaries do not open. Because the Mech. side of a Vac. secondary dose not open on any Holley THAT I have Ever seen The slot is to LONG for The Linkage to open it. So the spring for the vac side may need to be played with. Another thing also comes to Mind is what size fuel line are you running. Even though the stock line should be fine for a stock to hot street setup.
God doesn't like ugly.
