From the way yu explain that it sounds as if you have a vacuum leak. If I were within 50 miles I would come take a look for you. Original B's run at about 11:1 air/fuel ratio in my experience, so even with a big vacuum leak, it will still run.

Devin

If you can't hose it out it ain't a truck

55 3100
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64 El Camino
72 240Z
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