Post 233 on to 239. He mounts the tip of his exhaust in the end of the slider, right before the rear tire. Turned out real clean and saved some space. Maybe you could do something like this, right before your Uhaul box?
BTW, just read through your ENTIRE build, good stuff..subd.
One of my favorite shows is Full Custom Garage with Ian Roussel. He builds some very cool stuff. I just watched the build of a military truck with a box on the back. Check it out!
Helping to build a truck for SEMA. Crunch time! F250, 4x4, crew cab, short bed. I will be shooting it for Offroad Extreme right before it ships this weekend.