Hmm. Let's see. Do you run other batts that could be smaller and fit better into the chassis? How much real estate do you have around the battery compartment if you were to get out a dremel? How is the battery held down? Does the current battery tie-down allow movement of the battery in any way? What is the battery case in the area causing the problem made out of? If plastic, look at maybe sanding it down? I don't have a truck anything like it,so let me know what works and what doesn't.
RC13