I've been running the BFG KM MT's in the 285 size, that are D rated, since I bought the truck in '02 with no problems. The load rating on the 285's was one of the highest in the line up at 3305 lbs on singles and my factory 265 Michelins, E rated, were 3415 lbs. I use the truck for for hunting trips towing a 2 axle 7000 lb trailer that is usually loaded to the gills and to tow our 28' Sandpiper 5th wheel that is 6750 lbs. dry and 11,500 GVW. I do like having an aggressive tread tire. I was the only one in our group of 3 trucks to make it into camp in Idaho last year without chaining up. It was a slight up hill for about 200 yards with melting snow,slimy mud, and we all were pulling trailers. The other 2 trucks were Ford Powerstrokes and I had to give my buddy's crap since their Ford's couldn't make it without putting chains on, but they were both running the factory all-terrains. I also worried about going to the D rated MT's but I've been very happy with them. There is alot of personal preference about tires and I like the looks of an aggressive tread tire on a 4x4 truck. The new Toyo MT's look good and are E rated, but a friend of mine just put a set on his F350 and we both noticed the stiffer ride with them. Anyways I've been happy with my choice with the way I use my truck.
Regards, Mike.