[Mikeinnj]

The previous owner may or may not have installed a "pencil " or "Micro-Filter" at the bottom of the gas tank which would be located where the fuel shutoff screws into the gas tank. It is a press fit and filters all the contaminants found inside the 90 year old tank. My car did exactly what yours is doing at highway speeds. Drain the tank and remove the gas iine and pencil filter and fill and flush the tank with a gallon of fresh gas and install a new pencil filter. I was amazed how much sediment came out of my tank and it was clogging the filter causing the lean condition.At least this is a starting point to insure that the tank/filter are clean.