I'm completely un familiar with the bigger/older trucks maybe more so than you, but I have to think it would be a tow issue rather than sloppyness, given your description of everything. When it is sitting still do you have excessive play in the wheel? If not, then should only need alignment (don't know how 'cause i'm not there yet). I would bet that most alignment shops (not pepboys or auto zone) would take it on and figure it out. In our area there are enough farmers that these don't present that big of a problem for those in the know.
