I got 265/70/18 (32.6") tires to fit on non-F-sport factory GX rims (18x7.5, +25) with no rub. I did push the front inner fenderwell 1/2-3/4" forward by moving screw holes for the outer, bottom 3 screws that connect the liner to the front bumper.Just an update, I was able to fit a set of 275/70r18 KO2's with minor rubbing with Bilstein 5100's set at the second notch (0.85"). No rubbing on the body mount and just a little massaging on the fender liner.
On the rear side of the front wheel liner, I removed the screw everyone talks about, popped out it's recessed thread piece, and put in a metal bolt instead that I was able to attack to zip ties and pull back from behind to the running board frame bracket.
I have no lift, but no rub in any instance, and over 1" clearance to inner fender through full steering wheel location.
Do you have any rubbing on UCA at all with 275/70/18? Ever check for the tell-tsle shiny spots on the UCA? Are you running standard wheels with standard UCA? Some people with 2nd gen GX reported some UCA rubbing with even 265/70/18.