I have a 2004 Limited 4Runner 4WD which I have had 22's with low profile tires on for the past 2 years, but I want a change so I'm thinking about getting all-terrain big tires, but I dont know how big I can go without a lift or what size wheel I will need. Does anybody know what the largest size tire that will fit a stock 4Runner is?

not 100% sure but 31x10.50 fits with out any mods, I have heard that a 32x11.50 also fits but I would be hesitant. Besides you pay a lot more for an odd stocked size like that.