Ok guys what could cause only my passenger tire to be leaning in. I have a 2500 6.0 with 9 inch lift on 35's

 

Gmc sierra

 

Provided the truck body is level meaning no broken suspension parts like springs etc. If the tire is leaning at the top it would be the camber adjustments. If the front of the tire is moved in it would be your toe in adjustments. Assuming it's camber check the adjustment cams to make sure they are not loose. They should be on the lower control A arm where it's bolted to the frame. They are off set round about the size of a silver dollar. You might want to measure the height of the control arm to ground and compare both sides. You may have a weak spring or other suspension problem.