For most tires, 245/75/16 measure identically to a standard 31 diameter wise. Most 31s are about 30.5" in diameter. These calculate to be the same. For the Duratracs, they are identical given Goodyear's specs. The width is obviously less, but a 245 mm width pairs up perfectly with a 7" wide rim. Most manufactures measure this size on a 7" wide rim. I'm pretty set on that size. Anything is going to look bigger/better than the 29s I have on there now. Take into consideration that I still want to be able to flex without trimming. 265/75/16 is 31.6" and 285/75/16 is 32.8". No way would I put my D30 up to the task of spinning 33s. I also don't want to lose a bunch of power going up in tire size.
01 TJ - 4.0L, NV3550, 2" Skyjacker budget boost, Xenon flat flares, Trail Gear front bumper, Tuff Stuff rear bumper, RH4X4 sliders, 33" STT Pros on 15x8s