Not my first choice of lockers, but it's essentially free so i might as well use it. It's currently in a 3.73-down carrier, I need to put it in the other carrier so I can fit my 4.10 gears.
I have one in my D35 TJ. Its noisy as far as the clicking goes as you round corners but I believe most of them are any way. Its done what I need it to do. Its free for you so take it.
Make sure you mark all the caps and shims so you can put it back together. Depending on the mileage of our axle, it may not me a bad idea to put all new bearings and seals. If you do that then putting it in will not be as easy.
All you have to do is tap put the cross pin and the the holder pin. One is small and the other oviously big. Its a spring loaded assembly so expect it to spring open, and follow the install instructions for putting it back in because, it has a certain order or it wont fit. I did a lock right in my toyota 4runners rear axle with 4.10's and it only took me 15 mins its almost identical to the aussie you should be alright