Go to
www.coral.net they have a tech section on how to install the 3G alternator.
If you have an external regulator then it might not help you.
I did an alternator upgrade on my 82GT but I got unit from Powermaster with just a one wire hook up. I ran a 4 gauge wire from the battery to the alternator and was done...nothing else to do!!
They make 100 and 140amp units and just a s good if not better than the 3G
Let us know how you do.
------------------
'82 GT 351W C-4,BBK headers,Carter 625 carb,Comp.Cam,Flowmaster exhaust.
1988 GT...T-5,bone stock