The story about the vacuum advance port pulling vacuum went away after I removed the lead plugs in the carb, and adjusted them for the highest vacuum reading. There was no vacuum to the advance can after that because I was able to lower the idle.
After I did this, I replaced the whole carb with another one; a Competition Series Edelbrock. The car acts the same (maybe a little worse) with this carb.
No, I never disassembled the engine. It has never been opened up except for replacement timing chain/gears, oil pan gasket and timing cover gasket. It still has the foan intake seals from the factory. Uses NO oil.
George