Jwestpro
Explorer
Looking at 275/55/18 KO2.
To be clear, I'm not sure that size even exists in many, if any, AT tires. If it did, it would also be a very difficult fitting for the many documented reasons.
Best sizes are the following on 8" best, to 8.5" doable but starting to limit clearances, 9" asking for trouble with no real benefit, 9.5" poser time with purely looking cool while significant reduction in tire size functionality.
Basically the wider you go, the less tall you can go, or vise versa. All notes are assuming a person wants the most possible function off road in articulation situations. Gravel roads and mall crawling can pretty much run whatever doesn't grind the control arms.
265/60
265/65 31.5"
255/70
265/70
275/65 32"
275/70 33"
285/70 34"
As sizes increase, more modifications will be necessary.