8 3/4 axle out of c-body

I'm thinking about buying a 8 3/4 out of a 1968 Fury. The car is up in the air and when I rotated the wheel the drivshaft didn't move. The opposite wheel turned but thats it. Any ideas what's broken inside that would cause that? I can get the rearend for $90.00 and would plan on cutting it down to shorten it. I'm just wondering if the third member would have major damage to not be turning the driveshaft. Jayson