I just now tried some 265/70-17 tires that were pretty well worn; measured 30" at the edge of the tread (got them used with some Taco wheels). they fit, but rub against the running boards and a small portion of the wheel well:
I do intend to take the running boards of and replace them with rock sliders. But there is still the portion of the fender to contend with.
I was testing this size because there are several slightly used 265/70/17 AT tires on FB Marketplace for a good price, but it looks like I would have rubbing issues. Plus with more tread on a newer tires, maybe more rubbing issues.