This pic is from the fender install on the Stalker, but it clearly shows the factory seams that need to be folded over.
The vertical seam looks almost like a blade, and it acts like one when a larger tire gets too close. This needs to be folded flat (using a hammer) pushing towards the engine. Follow the 'blade' all the way up and around the fender.
The other seam is horizontal and can also be seen in the picture. This can be 'folded' down and away from the the tire. That whole section can be massaged a bit to push the firewall back away from the tire.
On my trail rig, the front axle is pushed forward almost 6" due to the YJ suspension conversion and redrilled perch mount points. It is pretty evident in this pic...
