I have the same truck and just bought tires for mine about 6 months ago. I was looking for the same size and ended up going with 285/75-18 in a nitto dune grappler. It's actually a "sand" tire but I've been in some good mud with them and they do great. I got them from eBay for $825 to my door. Tires for an 18" rim a crazy high. Hope this helps. My take offs where trash so I don't have them any more.