I think boatpuller is referring to the 3" drop spindles. Some have a slight clearance problem between the lip (or gutter) of the LCA and the rim. How much to grind depends on the diameter and backspacing of the rim. As Slon reported, those that use the 2 1/2" spindles don't have this issue. BTW, you could always step up to a 17" rally or smoothie. Although, I'm not sure anyone offers a truck rally in 17".
BTW, a 8" front and 10" rear wheel setup would look nice.