This FJ has a Procomp 6" suspension lift, with 35x12.5's on 18"s. I'm told 20" wheels will fit with this lift...if that's the case, why not 37"'s (maybe with only 10.5 width) on the existing 18's? Obviously, all of the trimming to allow this has been done. Any opinions would be welcome. Especially in regards to gears. Thanks