A buddie just pulled a set of heads off a 440 that has been lying around in his garage a while .. he called me and said he never saw numbers like this .. ..One head had 3462846 But the other head numbers were 1836AWJ..never saw that before .. any ideas on them ..what are they ?..I haven't seen them yet ,,,don't know if they are open chamber or closed,late model, hardened guides ??