I haven't been here in a while, so I'll chime in with a few points... First, almost any new tire that comes in a size that would be applied to a 3/4 ton+ truck is going to be Load Range E. This is because a D tire doesn't have a high enough inflation pressure to allow it to be inflated high to turn off the TPMS warning of a new truck. That's just the way it's going to be. Actually, when the 255 BFG gets re-issued in May, I'd wager a case of cold ones that it'll be LR E too.
Fargo, if you really want to make the move to 17" wheels (Which is directionally wrong for off road use IMO) there is an option you may not have considered... You can get 1.25" thick adapters that are Hub Centric on the TJ, and Hub Centric for JK or WJ wheels. Because JK's and WJ's use about 1" more backspacing than TJ wheels, you'll actually end up only increasing the track width by about 1/2", not by 2-1/2". You just have to find a good set of adapters. When installed correctly, they are functionally equivalent to having 1pc wheels with the back spacing and pattern you require.
I just made the switch from 285/75R16 D STT's to 255/85R16 E Maxx's, and I couldn't be happier!!! The ride is BETTER, not worse, and the tires are performing awesome!! I think the sidewalls are no stiffer than my old D's, which jives with what I was told by Cooper at SEMA this year. I don't miss the width at all, and mileage seems a little bit better. The Maxx's don't make noise. I'm serious. I can't hear a thing out of them. The new Fun Country's that I have HOWL by comparison. Performance offroad in Moab and Colorado has been stellar, equal to or better than my STT's in all respects. I suspect that the STT might be the better mud tire when the going gets snotty, but I just don't see much mud anymore.
I mounted them on the same 8" wide wheels that my 285 STT's were on, and they look right at home. The Maxx's tread width measures closer to what would be considered a 265 tire, just like the Toyo MT.
Chris