26x7.5 Is that a MT drag tire? MT lists that as having a section of 6.3"
225/60 is about 9" wide.
5.25" wheel w/ 3.5" back has 3/8" offset and results in 3.15"- 0.375", or about 2.775" tire outboard the rotor face.
His 7" w/ 4.25" back has 1/4" offset and results in 4.5"-0.25", or about 4.25" tire outboard the rotor face.
Assuming the same suspension / brake combinations your tire is farther inboard by about 1.5", so it likely clears the front edge of the wheel opening, where if his tire was as tall as yours it would not.
Turn your tire in to where the outside edge lines up with the front fender edge of the wheel opening, that is one tight spot, then turn the other way and see how far you clear the bolt at the back of the wheel well opening. That will tell you how much clearance you have.