Dward,
There is no problem with clearance if you have the 3rd generation with the 265/70/17's. The 5th wheel that I tow weighs 9,250 lbs dry. I bought the Michelin LTX AS. I tow with 65psi in the front and 75 psi in the rear. Will go down to 55psi in rear when not towing. I like the ride of the Michelin. They do pick up a few rocks. I'm very happy with them. I pulled across the scales the other day while towing and with just the truck on the scales the weight was 10,280lbs and the trailer was 7,980lbs that gave me a gross of 18,260lbs. They are not much wider than the Goodyears that I got 57,700 miles out of and still had some life left in them but with winter coming on I bought the Michelin's never cared for Goodyears. If you have any other questions please fel free to PM me.
Craig