[James]

It still sound like you are not getting enough fuel. I think you have a plugged main metering system. I could be from the sitting for a long time (old fuel can cause this crusty build up) or something had gotten into the internal passageways restricting the fuel flow to the boost venturis. I would disassembled the carb and check that portion of the circuit from the main jets to the boost venturis. You might get lucky and it only the main jets plugged (being they are in the bottom of the fuel bowl).