We don't have any custom fit hitches for a 1956 Ford truck but I do have a universal hitch that will bolt to your truck's frame. It is the Draw-Tite Ultra Frame Service Body Trailer Hitch item # 41990-07. This 2" hitch can be welded or bolted onto your 34" wide frame.
I have linked the installation instructions below so you can see how to get it set up. You will want to skip ahead to the diagram 2 step to see how to get it installed with bolts. view full answer...