I recently measured the rear end under my 2009 Chev 2500HD. It is disc brakes, 3.73 posi and all the dimensions are close enough to my 1950 GMC 3/4 ton so that I could easily swap. Even though I'm not very active in the salvage business any more, I still watch what salvage brings. Hard front hit 3/4 tons with single tires don't arouse much interest. Of course this doesn't mean a salvage dealer will sell the rear cheap if he knows you really want it.
