Problem solved. Issue was a lot more complicated than I expected. It involved the battery, voltage regulator and the coil. First, I determined that the battery would show 6.5 volts at rest and when running but if the amperage draw would increase for any reason (directional signals, brake lights etc) the voltage would drop to 4.5 volts. If the car was running for 10 or more minutes the voltage would stay at 4.5 volts. This told me I had an intermittent cell in the battery. I changed the battery and the problem was still there but not as bad as before. I did not like what I saw with how the charging system was working so I then did a cleaning and adjustment of the voltage regulator and that indicated that the regulator was not operating properly. I replaced it and that solved more of the problem. Next I changed the coil from the new one to a known good spare. Bingo, problem solved. She runs like a top. NAPA gladly swapped out the bad, new coil and now I have a good running car with a new battery, coil, and voltage regulator.