Your vacuum advance is fine if it moved with just a couple of pumps. You should look at some other cause. After rereading all your posts I believe you have a fuel problem. Somewhere or something is partially plugged up. Check flow at the tank then at the inlet of the pump then the outlet of the pump. If all those areas are flowing freely then you probably need to open up the carb and have a look.
Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
| 
