reg or rec

Ok, time for confessional... When I first bought my '86 Max this spring, I immediately ordered a new (stock) reg/rec to attempt to fix my charging problems. I have since found this and other forums that would have changed what I did, but now I am replacing my stator and battery for good...

I have a friend who has an 85 and he's having some starting issues, we did some research on the web and foud that a rec/reg from a 1996 and up greatly inproves the starting .....However the old one has: 3 white, 1 red. The new one has: 3 white, 1 red, and a BLACK wire. Do I just ground that...