Transfer case mount question

[powerwagontim]

When I disassembled my truck a couple of years ago, I found one transfer case mount different than the other 3. It was steel and rubber, but fused at the factory, and a larger diameter than the standard rubber ones that slip over the steel bushing. I have also parted out M37s that had this same mount, as well as others had all the same mounts all 4 corners.
2 questions. First, I cant remember which corner the odd ball goes in, and second, whats the reason for the odd mount? I couldnt find any clarification in the manuals.
Thanks,
Tim