This is such a common problem, there are kits to flip the axles. There are also shackle lifts for when the flip isn't enough. Just work those items into the deal if needed. You could use them as incentives for the sales person. eg, "If you throw in the axle flip and installation, you got yourself a deal."
2014 Ram 2500 Mega Cab Laramie 4x4 6.4L HEMI 4.10s with antispin
2014 Jayco Jay Flight Swift 287BHBE
Equal-i-zer 90-00-1200(new 90-02-4900 shank)
2x Honda 2K