After reading this thread, I decided to go with 285/75R16 Firestone Destination M/T tires. I was really please with this size and tire selection. The taller tire reduced my engine RPM's at highway speeds and the M/T tread isn't too loud. The tire cleared mud well and kept the truck going on a muddy trail ride last week.
The first trail ride out I was listening for the tires hitting the fender, but didn't have any problems. I did some "test fitting" in the front yard and took pictures. I would have to say 285/75R16 is the largest I would go without a lift no trimming if you actually plan on using offroad. The closeup picture looks as if the tire is hitting, but it actually wasn't.