72 Duster, Ethanol gas, intake backfire

Mattax said

All our current pump gas has poor storage and loses its light end easily. The light end of fuel is the stuff that vaporizes easiest. Think of it like the tinder and smallest kindling when building a camp fire. Take that away and its much harder to get a good fire started.

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Here is another symptom that I forgot to mention.
It may be unrelated or possibly a different problem but even though there is a healthy accelerator pump shot, the car is very hard to start. I had to spray carb cleaner down the throat to get it to fire. I did this several times.