I finally discovered ALL the issues causing my rotor grinding. 1st was the pad carrier part of the re-built calipers I bought from Napa. They were not square to the rotor causing the whole thing to ride cockeyed. I had to square them up with a file to fit correctly. I should have known that the powder coating was hiding something, and that something was a badly tweaked carrier. I thought the powder coating was a bonus, but it was actually there to hide the badly corroded caliper parts. 2nd was the used ( but never installed) Trail Tough disc adapters I purchased from someone on the Zuwharrie forum. They had over 1/16 " runout and although that doesn't sound like much, carry that out to the edge of the disc and it was enough to make it rub. A machinist buddy of mine trued them up for me and he couldn't believe how far off they were. He said it may have something to do with how they were cut. The lazer cutting method used on these may have heated them up enough to warp the steel. Or maybe it was just crappy steel. It definitely heated them up enough to harden the edges and ruin one of his cutting tools! That's something to keep in mind if anyone is going to do this mod, especially if you drive your rig on the highway. Before you install everything permanantly, check the adapters for runout. Oh, BTW, it WAS NOT the wheel bearings.