Room with my 5zigen zr520. They are 8.5" with +30 and I have at least 1.125" of space to the calipers and at some spots 1.25". I know different wheel spokes/pattern obviously come into play here but let's say keeping the same wheel my 5zigens, if instead of 8.5" +30 they would be 8" +42 like the weds, how much closer in would they get?