I own a 370FB and took it on it's first 400 mile trip. I purchased the 8,000ln axle upgrade and the disk brake option. The brakes on 2 tires fell off and damaged the rims. Dexter did a great job making it right and I had to order 2 rims from Alliance. What people need to know, is any manufacturer that sells something with tires on it, do not balance the tires. When I put the new rims onto the tires, one rim needed 5 1/2 ozs! So I am suggesting that one should consider balancing the tires to reduce stresses on bearings, frame, ect ..... If you have a 17.5" tire, take it to a truck center. The automotive places usually can't handle the larger tire.