Strange feeling/sound when stopping...

This is a fairly odd one and I can't figure it out but it is annoying! I have a 92 Jeep Cherokee inline 6 with 4wd and ABS. Almost everytime that i come to a normal stop at the point right before your wheels totally stop it feels like the rear end of the car drops like an inch or two with a slight bang vibration. I have put new shocks on about 5 months ago. In the rear I have three inch blocks. I have checked the tightness of my Ubolts and my leaf springs. Also I have a one inch transfer case drop. Then when I start going again right away it seems like it bangs out of it. Possibly autotranny? rear drums? Rear gears in axle? Thanks

bad u-joints in rear ds or warped drums.....maybe????