I agree 100% with gom, but what's done is done. I bet you could easily do a one for one swap with a fellow member with 20's looking for your wheels and tires. FYI, your tires are 34.83 x 11.22 - 18 and the stock 20's are 34.07 x 10.83 -20. So the 20's are only 3/4" shorter and 1/2" narrower. I personally would stay with the stock Tremor tires. I had almost 60,000 miles on my last set of Duratracs, and most of the miles were towing my 38' fifthwheel and 20' enclosed trailer. I really liked the tires.