Need carb help on my 72

[bmfm64]

So I bought this 72 a while ago now and finally got around to driving it further than just around the yard. It idles awesome and cruises around the yard just fine. The issue I have though is as soon as you take it out on the road and go more than a mile or so it wants to die every time you come to a stop. It will start back up but you have to pump the gas a bunch and hold your foot on the throttle once it gets goin and drop her into gear to get rollin again. This truck sat for 11 years before I bought it... truck is a 72 3/4 ton, LWB, 350/350 truck all original except the carb. Carb is an Edelbrock 1406 with electric choke. After truck has sat for a while I shine a light down the throat of the carb and operate the throttle with the motor off and don't get the usual streams of gas. Not sure this is part of the problem but I'm assuming an accelerator pump maybe? Any ideas?