Wrong Alternator?

Let me put this simply........Generally speaking the squarebacks charge better at lower RPM. But with ALL Mopar alternators, watch rebuilds like a hawk. They often LEAVE OUT hardware or otherwise incorrectly assemble brushes, causing what should be "isolated fields" to become "grounded fields." ALWAYS CHECK the field connections with an ohmeter to make sure they do not go to ground on isolated field units

You can intentionally ground ANY isolated field unit and us it with a 69/ earlier regulator.

You can add just one wire and convert a 69/ earlier car to use 70/ later alternator and VR