What type of Termignoni exhaust kit is it? Full or slip on? If it's a full you can try loosening up the manifolds, everything....leave it all loose and see if you can pick up some space where it's rubbing. If it's a slip, it shouldn't touch at all. Maybe you bought the wrong kit w/ the wrong horz. pipe.....that said if it's just wearing that rib on the old style sand cast swinger then let it wear itself in.