Got it rebuilt and supposedly tuned and ready to go from the seller. it is weirdly dripping - take a look at the youtube video please and tell me if this looks normal
Looks like accelerator pump is working ,quit pumping when not running its leaking around shaft from no vacuum from motor not running probably some wear in throttle body housing to bottom butterfly shaft or side thrust wear as round butterfly's center some carbs have felt shaft seal for this and have seen nylon washers to seal better . Mines at tarp shop or I could look as manual doesn't show any and when I rebuilt mine I didn't tear down that far .
My 2bbl Rochester did the same thing, apparently known for developing leak there at pump shaft. I had mine rebuilt and they fixed that also. I would speak with your re-builder. Like I said, known issue.