My 68 "maybe" Z/28 has the dual exhaust rivnuts, but the upper location has the bolt/screw head broken off? Its small ! I've tried drilling it carefully with no luck I'm afraid my bit has already got into one side of the threads on the rivnut. Not sure how to proceed?
? Help I know we should not cuss on here but holy @$×%%#$!×@€£₩&%