I centered the wheels on the lugs like someone mentioned (and like you're supposed to do with a 1st Gen dually), and took it for a spin. No change. Jacked it up, spun tires, and both tires have about 1/8-3/16in bounce/bob to them. Took them off, and put some used tires on some other wheels I have. One spins smooth, and the other has about 1/16in bob, which considering the tread (or lack thereof) is no suprise. I thought Michelins were good tires, but these sure as heck aint. Guess they will go on the back of the 90; sure dont want them on the front- it'll never sell.
-DP