1991 Ford F-150 Grounding issue?

This truck is only driven a few times a month. The truck starts up strong with no hesitation. If driven for a few miles where everything is warmed up and I shut the engine down, the engine
struggles to turn-over. When trying to restart, the ground wire from the battery cable to body heated and burned up. I replaced the entire battery cable.
I cleaned the ground points to the body and frame. The ground to engine I could not reach so I added a second cable from the battery-to-frame over to
the block of the engine. The issue still remains. If cold, the engine starts up quickly. Once warmed up, struggles and burns up any small gauge ground wire to body.
I need to wait about a half hour before the engine will start without issue.