Help! Edelbrock problems...

Scene:
1406 Edelbrock 600cfm 4-barrel carb electric choke.
Sitting on a 318 with a decent cam.
Electronic ignition with vacuum advance.

Problem:
Carb is drowning my engine, after engine stops running the carb is still feeding gas from the primary venturi boosters. I'm looking for some input on this as I have rebuilt the carb, checked the floats and idle-mixture settings. Was given the suggestion that it may be due to the aftermarket cam and vacuum advance not cooperating? :wack: