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I would think you could find someone or a company that does truck frame altering or mounts dump boxes. There is a company here in Des Moines that builds dump boxes and mounts them and also installs hitches for pup trailers. I know our pups use a pinnel hitch but the same type attachment would be used when attaching to the truck frame. You might try a truck junk yard because there are some factory installed hitches that get taken off if the end user won't need them and they take them off to save weight.