I've always had concerns over taking a grinder to a calliper in the way suggested by some posts. A friend of mine who designs and builds HGV brakes tells me you shouldn't remove anything more than casting marks (which actually removes a point of weakness). Anything else removed compromises the integrity of the calliper. It's up to you at the end of the day, but is it worth it just to keep Ford 15" wheels? Plus I wouldn't want to face the insurance company if they ask why the callipers have been modified in such a way after an accident.

Lee