howdy,,
I do belive that powrlok makes an upgraded LS/Locker for 8.8 with LS carriers,,
I am more familar with the Dana 44 as apposed to the Ford 8.8,, because I have a couple of IH Scouts I am always beating,, but I do beleive the situation is the same. If you have a Dif with a factory LS in it,, then you are kind of limited on which lockers you can put in with having to change out the carrier.
Lets say you want a luch box style locker like and Aussie locker,, nice locker for under $250,, and a real locker,, which is night and day over a limited slip or 'clutch' type locker. It will not fit in an LS carrier, it can only be enstalled in an "open"carrier. The open carries are only like $60 new,, but you will have to set up the gears again. If you get a Detriot, ARB, OX, and so they are built around their own carriers and seting up the gears is implied.
You might see if you can find a powr lok for an 8.8 LS that does not need a gear set up. It will be a much tighter lock up than the factory double dog clutch. I have an 01 ST with 4x4 LS and 4.10s.. and so far the LS has worked very will..
Good luck brother