I know more about the gen1 but I also own a gen2. The early SRs 92-93? have open diffs, not sure the locker was a option. The factory lockers are pneumatic. I dont know about locking in hi and low, I guess you could bypass the controll thing. On the larger front diffs, again, not sure the years, you can get an ARB. ARBs are also made for the rear, I have one in my 93SR. Others will jump in and fill in the gaps. I do know the big rear axles have a 9.25 in ring gear, 31 spline, 35mm shafts, that is fairly big.

I just want to tell you both good luck, and we're all counting on you.