[DRJDVM's '69]

Alot of frame rails start to kick out laterally as you get to the rear of the car....in other words they dont run parallel with the wheel opening....so the outer wheel opening to inside edge of the tub is alittle smaller in the rear. Not a big deal until you try and stuff a big tire in there. Then it can often be the limiting width. So alot of guys take a piece out of the frame and make the frame alittle more narrow in that area, so you have more side-to-side width to get the tire in there....

Does that make sense? I have pix but not via a link...