I am seriously looking to take the full spool out of my 8.8 and replace it with something more street-able. My 8.8 has 4.88 gears and chromo shafts and i believe it has c-clip eliminators.
After driving on everything from a welded diff, to a LSD, I would never consider anything except selectable from now on.
Try to find a used ARB if funds are tight, but I would highly recommend a selectable locker of some sort.