I was wondering what kind of rear diff is in my stock 95 6.5L 2500 Sierra 4x4 because I've been looking at the HD2500 trucks and they come with a posi rear. Not sure if mine is just a regular open diff or if its some sort of weak limited slip. can anybody tell me. what kind of options do i have for making it a posi rear? make just get the diff from a newer 2500 HP truck and make it work with the right gear ratio