I would put my money on the problem being unrelated to the pump shot.

First be ABSALUTELY CERTAIN that you don't have a vacuum leak somewhere.

Next, check that your ignition is healthy and that your distributor vacuum advance is working properly.

Next be sure your fuel pump is good and filters aren't clogged.

Be sure your gas is clean! MANY fuel related issues these days with rust or varnish and junk in the old tanks making thier way to the carbs, as well as just modern fuel blends going bad faster than expected when sitting in a stored car.

If all else seems healthy check your float levels first, then reset your curb idle speed (the big air valve screw in the center of the carb base), then reset your idle mixture screws using a tach or a vacuum gauge shooting for peak numbers on each. See if that gets you anywhere.