if rods are stock they should be number if billet rods use a etch pen do not stamp them. if rods are just stock use a number stamps you can buy them cheap .if you have better rods they may not be numbered as to fire order they many times have a code number so no need to number them do not punch them with a punch not the way to do it and really piss.s off the guy at the machine shop if they need to be reworked