2-3/8" in front over stock on an 09 4x4 and a mild PWM and i clear 295/70/18s bump to bump and full turn, However, i'm not sure with that offset. Also, my front bumper has been modded, half the steel is gone, the edges trimmed, and those tin tube supports are removed.
if you're just after the look, then going wider would be alright, but keep in mind that if you're seeking traction off-road, the wider is not better, unless you're heavily into loose sand. if you're just tooling around town in it, then you can probably clear them with just a little bigger spacer on the coils, or mid-5100s and a 1.5" spacer, but if you get flexed out you'll rub pretty bad, most likely. All in all, if you're going for just the look, there won't be that much a stance and visual difference between the 275s and the 295s. the 285/65/18s will fit a post 08 4x4 bone stock, (I ran them for four years before any suspension work or body mods). It depends on form or function what to chance, IMHO, I'd stick with the smaller tires unless you want to add more lift. Listen to pa-pro on this stuff, I once didn't, and it cost me a couple hundred and some major headaches. Good luck.