As I understand it, they are the same motor, just tuned differently to compensate for the heavier G-50 transmission. I'm sure somone with more expertise will clarify exactly WHAT is different.
EDIT - John was faster to post than I
Also, I could swear that my '87 weighs in over 3400 lbs, not the 2756 listed above?? Maybe due to the fact that I have power items, but 700 pounds? No wonder it's called a pig
I'll have to check again tonight.
-Chris