Killing Dist pickups ?

The thing that could kill them IS A FAULT IN THE IGNTION BOX. The pickup should NOT have much if any voltage/ current through it. It is essentially a magnetic generator, which sends a signal to the box. But something wrong in the box may be passing enough power through the pickup to cause failure.

What is the connector? If this system uses the usual Mopar rubber 2 wire connector, they are a suspect deal. Inspect for corrosion with a magnifier/ light, and work the connector in/out several times to scrub the terminals.