On the 2013-up 3500s and the 2014-up 2500s, the gooseneck bolts to a monster crossmember of the frame that was designed to hold a gooseneck hitch, either factory or B&W mount the same. The B&W Companion fifth wheel hitch plugs into the gooseneck hole, not rails that bolt to the bed! Yes, it has rails that rest on the bed but does not rely on them for all its strength. I wrote it up in detail in Issue 83.