My brother bought an 85 pickup not long ago. We have now come to realize that he has an externally regulated alternator with no external regulator on the truck (nor did it ever have one wired in).

So, any suggestions one WHICH regulator to buy and what the EASIEST way to install it would be?

Also, I was told by the guy at the parts counter that they came in 5 pin or 6 pin... which would he need?