Overcharging Problems?

OK, and I would think that your regulator "should" be fine for that alternator, BUT there is a possibility that the regulator is bad

Another way to check for voltage drop is to make up a great big jumper clip. Get some old fashioned alligator clips like you'd find on about a 20-30A charger

Jumper directly from the pos. battery to the IGN supply of the regulator and see if the voltage goes down

Jumper directly from the battery neg. to the frame of the regulator --make sure you get through the paint -- and see if the voltage goes down.