Wendell,
Yes, there was lead in gasoline, "back in the day". It was a cheap way to cheaply raise the octane. It was also an effective way to raise lead levels in living organisms (in plants & animals, and in water).
Use regular gasoline in our low-compression Stovebolt engines - Chevrolet 6-cylinder 216, 235, 261 (and, earlier 6 cylinder).
Do not worry (much) about ethanol (10% does not seem to cause much harm). The only additive you might want to use is something like Sta-Bil in a full tank of gas, if you are not going to drive your truck for a month or three (winter hibernation, for example).
If you want to see some question-posting-fire, ask about ZDDP being necessary for Stovebolt engines.
