From what I have gathered, you want the two mounts (towed vehicle) to be 24" apart. The body mounts are 26" ish apart. So, what if I sandwiched an piece of 90* metal under the body mount. Then bolt a tow bar to that.

With more thought put into a design, along w/consideration of what happened to 79coyotefrg's friend, and given your situation of having to mount the bars near your body mounts, this is what I came up with(drawing not to scale),

This design is more like a traditional trailer tongue, and directs the push/pull forces experienced during towing straight at the mounts, rather than at an angle as with this style of tow bar,


Using a plate that is attached at both the body mount and the the front of the frame will distribute the push/pull forces of towing across the front X-member and onto the frame rails, rather than at the body mounts themselves, it would also save you from having to mount the brackets in between the body bushings and the body mounts.  Looking at the pic of your truck, I think 3" .250 flat stock should be about the right size to mount the tow bar brackets to.

The overall length of the tow bar is something that you would have to determine, I am not sure if they should be the same length/longer/shorter than trailer tongues for the flat towed vehicle to track correctly behind the tow rig.