I want to put the rear end gears out of my first gen(turd and a half) into my 87 second gen for the improved fuel economy....and the LSD! lol

I was just wondering if the 3.909:1 pumpkin out of the rear of my 1984 GSL 12A carb turd (POS) will swap into the place where my pegleggin' *** 4.10:1 pumpkin was I'm pretty sure its just a straightforward swap yank the axles, etc...but I just wanted some confirmation thanks!!

 

The 1st and 2nd Gen diffs are completely different, so no...