[gerfunken]

So, I actually went with a 31-gal fuel tank from a square body suburban. It fits cleanly between the rails. I had to remove the back two cross members, turning one around to provide the front mounting bracket. As far as exhaust goes, it looked like I had more of an issue from the rear brake line bracket than from the exhaust. I've got a little bit of room, but not an extreme amount, and will be looking at the exhaust routing next.

The mounting of the tank is one the last couple of pages, but I can always take more pictures if you need.