Ok so Ford tells me the company they had do the list kit is sending a steering dampner to install. Any thoughts about this???
like i said, a steering damper is just a bandaid fix, nothing more. something is loose and if the steering damper fixes it it is just hiding it. when it wears out (and it will wear faster because of the problem) it will come back.
if you tires say 50psi max, do NOT! run them at 70 psi. run whatever the max pressure is, but make sure you check them hot.
cupping of the tread (which is what it sounds like you're describing) doesn't come from not rotating your tiers, it comes from a chitty alignment. like i said in my other post, get a good alignment from a shop that knows 4x4s. good balance, alignment, and inflation are the best places to start. sometimes softer sidewall tires exacerbate the problem.
Paul
edit: i dont even know how you ended up at the dealer talking to them about lift kits. They are going to have ZERO knowledge and expertise when it comes to modifying the suspension on that truck. Hell, they probably have zero knowledge and expertise about the truck itself in the first place. Go to a local 4x4 shop. This is a very common problem with lifted SFAs, and any half decent offroad place should be able to help you track it down. Factory caster specs and everything else the dealer is going to try to do just dont apply anymore. That is, unless, they are paying for the work. Then let them throw their own money at it all you want, but they probably won't fix it.
See if you can get a hold of some stock rims and tires and go drive around. See if that does it. If it goes away, you know the issue most likely lies in the balance or characteristics of the tires you've got on there.
Sometimes the output bearing on the sector shaft of the steering box takes a crap, but at 12k that is unlikely.