The code # is the last 2 digits of the part #;
- 645-654g 911.103.015.31
- 654-663g 911.103.015.32
- 663-672g 911.103.015.33
and so on
the final digits are stamped on the con rod shank if it is supplied as a replacement part, weight of rods without bearing shells must differ by less than 9 g.