I have 235 75 15 AT2 General Tire. They fit nicely.
Found out by going on a small creek at home were I bottom out the suspension at the rear will rub a little with stock suspension. So with a 2 in spacer should do the trick. But if you drive off road and do nothing aggressive they do not rub at all.
So I can say that is the largest tire that fit with stock suspension. If I am not mistaken is about 29 inches Diameter.
Search for some of my post related to tire sizes, also there is a link to a nice tire calculator that helps you to compare tires in reference of stock tires (205-75-15).
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