At wits end!

That particular Holley 2bl was known to have accelerator issues. In the 70's I worked at a shop where we had the county contract to work on Sheriffs cars and support cars. So i have worked on many of these. Cudafever is right when he mentioned the fact that everytime you cycle the throttle, you are draining the fuel bowl. This is what I suggest. Start the car up and let the fuel bowl fill up, SHUT THE CAR OFF and proceed to look down the carb again. But don't pop the throtle open, move it through its cycle slowly. Gas should squirt with a smooth constant flow. If it doesn't( which I suspect it won't) You need to rebuild the carb. and look at the pump linkage to make sure it is moving the pump from the very start of the throttle being opened.