What treekiller is trying to tell you is that when the engineers at Chevy designed the car, they were thinkin' trunk space, not deep dish rims, so the space between the inner fender panels and the outer panels was designed for a relatively narrow rim and tire. In order to go much wider, you have to alter the inner panels. This is called mini-tubbing. If you want really wide rims and tires, you must cut into the trunk floor area/frame and tub the car, using a much shorter flange-to-flange axle housing.