Voltage regulator upgrade? Keep frying voltage regulators with swap

While what you fixed was a legit problem, it has nothing to do with burning up regulators or heavy field current. What was going on there is that the bad connections in your wiring harness were providing LOW voltage to your regulator, and the IGN terminal is not only power for the regulator, it is also voltage sensing.

So the regulator "sensed" that voltage was LOW and ramped up charging voltage to compensate. This is why I've got many many posts on checking regulator grounding and harness voltage drop.