Sounds like mine when I lifted it. Long story short, it was my drive shaft. I needed to convert to a CV type shaft even though my drive shaft angles were within limits.
I didn't believe it until after I actually tore my trans and cases apart and found nothing wrong. Finally gave in and changed the rear shaft to a CV type. Had to cut off old spring perches to rotate axle for proper CV angles. No more noise.
Rotating your spring perches may also affect your shock mounts and E-brake cables in some cases. Depends on lift and how much you have to rotate.
