I can't speak to whether they will fit on a Dually, but I had them on my SRW '04 and they were fantastic. They have a high load rating and are VERY quiet and smooth on the highway. They were great with my fifth wheel - about 2,100 total bed weight including both hitch and tongue weight. They are described as "Highway Terrain", not aggressive at all as far as tread patterns go, so no problems compared to a really aggressive (Terra Grappler) style tire. They remind me of the old BFG Sport Truck TA's, but more modern looking. They'll be going on my 2014 as soon as the stock tires wear out!