Is it possible to place your palm over the throat of the carb for a few seconds while rolling over, to check for vacuum, & see if it will pull fuel that way..??
Spark advance port plugged..?? No tears, or tiny pieces of the body gasket missing around the tiny internal passages..?? The Holley on my Ford 3 cyl. had a tear in the body gasket, and was doubled over, leaving maybe a 1/8" air gap, where a PO had apparently had it apart before. Had to choke it forever to get it started, then would surge. Glued it back in place with some gasket sealer, and eliminated the problem.