I have the firestone kit that mounts to the outside of the frame. B&W hitch too. The bags were on my other truck with a diff gooseneck hitch. When I moved them over to this 1, I had to space it out off the frsme with 2 thick washers so that nothing would rub. Grade 8 bolts and haven't hsd s lick of problems. The newer b&w's might be different than the real early ones like i have though.