I can tell you I had a used edelbrock carb that came on a pickup I aquired, and the floats loved to stick on that thing. Even worse than a holley that's been through the wringer, which I didn't think was possible. Those edelbrocks are copies of the old carter afb which a lot of guys older and more knowledgeable than me call JUNK.. lol. My experience with them made me want to believe it. Is the car smoking when it stalls, out of the exhaust? Can you smell raw fuel in the tailpipes? If so, that may be it. If not, check the above mentioned symptoms. They are all sound suggestions.
P.S. After rebuilding that eddie carb and still having the needles/floats stick like mad, I bought the cheapest summit brand 600 vacuum secondary 4 barrel they sold, which is a copy of an old holley. It purred like a kitten, and the eddie went in the scrap metal pile.