I have an 03 ZR2 blazer and oddly enough my rear passanger side tire sets in more than the rest? every other tire seems as were it should be, the rear driver side doesnt stick out more than the rest... I've asked several people and they don't seem to know, I've also seen a couple stock zr2 blazers and they might seem to set in a little aswell (Hard to tell when they are going by).

Is this a common thing? or is something missing/broken on mine to cause this? other than a bit of sag to that side due to a leaf spring, everything else is solid.

 

Anyone?

 

The first thing you should do is give the rear suspension a good check for any physical damage and then I would recomend takeing your truck to a good alignment shop so they can check all of the angles. If something is really out of wack it should show up on a computerized alignment. If you still are not happy with the read outs a body shop I think can put it up on a frame machine and check to make sure the frame is square. Good Luck!!!
One more thought, do you have a matched set of rims on the truck? If not could it be possibly different back spaceing and have you tried rotating the tires to see there is any change?