Toyota did manage to put different rear diffs into different models for different markets. Just enough to make things difficult. I also have no idea why. Maybe they where concerned with the extra Torque from the V6 , don't know why as they are a slug.
4 cylinders generally received a last code of 2 (non LSD) or 3 (LSD) which is a 2 pinon diff and the V6 generally recieved a final code 4 (non LSD) or 5(LSD) which is a 4 Pinon diff. Most G series diff parts interchange from the early 80s through to well into 2000s. Housings also have different widths.
I recently purchased a 92 130 series surf V6 with the G254 rear diff. 4.55 ratio and non LSD. It gets interesting when looking for options for LSD , pozi locker or air lockers. Some diff shops simply put a 2 pinon LSD centre into it which in my opinion is going backwards. We rarely have problems with 2wd owners with 1UZ popping diffs and the stck car boys over here use them without too many issues up to 500HP. This said 4WD boys with those big tyres manage to blow the odd one. These have two pinon non lsd items and are being very abusive to their diff ( big 2WD donuts and burnouts on seal)
My two cents worth with boosted vehicles is a tall diff works best. Justin runs a 3.72 in his celica from memory. One of our customers with a turbo 1uz in an EX lancer recently went from a 4 something diff to a 3.72 as well and he loves it.
Cheers