2005 Ford F-150 body leaning

I am considering purchasing this truck but I am a little nervous about what could be causing the body lean. The rear pasenger side of the bed is about 2" higher off the tire than the rear driver side bed. Up front, the driver side fender is about 1" higher off the tire than the passenger side fender. The truck drives smooth and straight and I couldn't see any evidence of damage. I don't even mind the lean as ong as it doesn't lead to costly repairs down the road. Any ideas? Thanks.