pretty much is what it is, im at a loss, 96 blazer 4x4 4.6, just redid the fuel pump, bastard went out, but beyond that yeah i dunno if its maybe the rear diff or tcase or even tranny making the noise but its not consistant once i hit 20 or 30 noise is gone, i stop at redlight and go its back then gone when i hit a certain speed, noise stops on braking or just letting off the gas, doesnt make noise when coasting downhill either so maybe not the driveline? ive also been tossing the idea around of maybe really cruddy drum brakes but hell i dont know, i aint changed them thangs for the 2 years ive had it any insight would be superb on this(sound definately from the back half of this thang)

 

fixed it, was rear ujoint, bastard barely moves tbh but that little 1 cm of wiggle is giving me the click of doom D

 

Glad you got it figured out!