I might be over my head here, and I hope an old timer can help out.
If it is an HEI with the integral coil, there is a ground issue. There is, I believe, four wires from the coil into the cap, and the wiring is critical.
If one of the ground wires is incorrectly placed in the grounding field in the cap, either it will burn an hole through the rotor, or short out the coil.
In an early HEI, it only has provision for three wires, upgraded coils that fix the burn out have four wires. An extra grounding strap is needed for inside the cap. I had to do this fix on my van. One day, when we had to leave our hotel as we were in the wake of Ivan, the van had no spark. I spent the day trying to get it fixed. Nada. I finally called an old mechanic who was reccomended and he told me how to patch the pinhole in the rotor. I got the van fired up, but we had to weather the hurricane in the hotel anyway.
The cap had the extra strap, but, it was together with one ground lead. I had to move the strap to another slot, and connect the extra ground lead to it.
No further problems.
It has been a while since I have done this, and I hope one of the experts can describe this in more detail. When I change coils, or internals, I automatically do this now. I haven't really thought it since Hurricane Ivan.