I had a 64 C10 which I had jumped the headlight power to the ignition - it was just a quick fix until I had time to find the problem. But, it did act as an anti theft device, as one had to know the headlights had to be on to start. To give the starter some extra power, I'd get the engine spinning first, then turn on the lights and it would fire up.

Anyway, just an old story, not a suggestion.