Yea, I got one of those in my bed. Being a former structural steel welder for decades, I can bet that without some cross members welded under the flimsy sheet steel bed, we'd pull that skin right up with a 1000lb load. Cross members can be welded in place and made from channel or even sheet steel broke to form a channel. The deuce crossmembers taper to the outside from about the main rail area, probably to allow for tire clearance when crossing ditches etc. So the farther out, the smaller the member will be. Having some 3/16 plate broke with the taper would keep the framework symmetrical, and maybe save on tire rub if there is a clearance issue when the suspension walks.