I'm converting my drum brakes to disc brakes on my 66 Rustang. Currently I am running 15X8 with 4.5 backspacing for the wheels and custom brackets and new cobra calipers, however the wheels don't clear the calipers all the way. My question is, is it a good idea to grind some metal off the caliper? Not too much, but enough for me to double check. Bye bye pretty red calipers, but I'd rather do that than blow more money on bigger wheels/tires. I need that money for the 5 speed swap.