Really weird ignition issue...
Yeah but that says nothing about why the vacuum advance was not working correctly.
Without having a properly working Mityvac, I don't think that I can trust the readings I get. Maybe I am using this one wrong? It had a receipt in the instruction booklet dated 1998.
Besides, if the newest distributor runs fine with the vacuum advance connected, that is some improvement.
Yes, I'd rather be the guy that can diagnose rather than the guy that just replaces parts until the car runs right. Sometimes it is a lot easier to "shotgun repair" when you have 10 spares at your disposal.
Still, yes...I do want to learn.
If the first distributor vacuum advance were actually leaking and not working, connecting the vacuum line to the carburetor would have just resulted in a vacuum leak. This was not that. The engine revved up and down, popped and stumbled and wanted to stall out. To me, that indicates a misfire situation.
If I'm seeing this wrong, tell me why. I leave room for the possibility of missing something.