Chad - the Aussie link I put up above is the one for the Gen1 Tracs (rear diff), but don't recall the shaft diameter for sure (believe it is 7/8) ...
As for why I prefer the locker - TRACTION, plain & simple. The '01 I had with the LSD, it was a little too easy to break traction. The open carrier was worse, but now with the locker ... well, put it this way ... the pic I have as the Snow Trac ...
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... made it up a steep hill with 10 inches of snow on a road that had not been touched by road crews (with several vehicles stuck at the bottom :lol: ) ... without loosing traction even once, and at about 25-30 mph !!! I was so impressed that I would even recommend getting a Trac with an open diff just so you can put a locker in it !! WORTH EVERY PENNY !! If you have 2WD, I would not hesitate a moment to get it, regardless of where you live/drive.
I drive mostly on road, but have a job that i have to get to regardless of the weather ... but I love the feeling that I can go anywhere I need to, on or off road ...