My buddy ran the 37's on his Dodge 2500 town rig with 750 ft/lbs of torque pulling a trailer with three rigs behind it... He loved them on his DD as a decent mt tire.
I have the load range E ones on my F-350. I thought the look would grow on me but im just not a flames person. They do alright in the snow and alright offroad but ive only been on dirt roads in my truck. JP magazine did an article on them and werent too impressed http://www.jpmagazine.com/techarticles/wheels/154_0704_nitto_dune_grappler/viewall.html