You take the bumper brackets off and use a dremel tool with a porting bit to grind away material to stretch the length of the mounting bolt holes in the bumper brackets. Really cleans the car up and improves on the fit and look if you do it correctly. I ditched the front rubbers the very day I took posession of my 73, I think that is the one thing the engineers really gave way to function over form and pretty much made it look like they beat it with the ugly stick.
