Well .. considering it is an empty differential housing .. you'll need to install gears and everything else into it. Otherwise it will bolt right up when its complete.
Swapped one into my 89SC without and issues. If you can get the LCAs with it that would help save about 50-70lbs on the rear end. You will need to install the Tracloc from the SC.
Thats what i bolted up on my 92 SC (5 speed) and kept the 3.08 that the mark 8 had but I did swap out the trac lok system. Wanted to do the lower arms also but was reading about the spring perches need so dropped that idea.
Forgot to mention that I haven't had any issues with that setup except that I need to rebuild the trak lok clutches and S spring.