I just installed 295/70r18 Toyo AT II Extreme tires on my 3500 Ram SRW and these tires are load rated at 4080 lbs. I think you would be good with your load, if you have 18" wheels and you don't mind buying new tires for a new truck. There are other tires out there with high load ratings, but you have to search for them. Truck Camper Magazine.com had a 855S that they went into great detail on the weight of the it and their 855S weighed out loaded approximately 4,100 lbs, you might want to check out their article on that.