Another edelbrock carb question!

On the disctributor - is the vacuum advance hooked up?
if it is: take a 7/32 allen wrench, remove the vacuum hose form the nipple of the distributor's can and stick the long side of wrench inside. You should feel it engage a hex down in the can. Turn it counter-clockwise 2 turns, and then reconnect and see if it still does it.
If it's not: remove the ignition cap and with a light look down under the advance plate (metal plate in the dsitributor) at the springs and weights. You may not see them well or at all depending on where the engine stopped turning.. but if they are grungy or rusty, you should remove the distributor, take it all apart and clean/lightly grease the advance weights and pivots. You may als want to look into the Mr. Gasket light advance weight package. It's the best $6 you'll spend on the car.