Ferrari Part Number 100124, 2ND UNDERSIZE 0.508 MM. ON ? shown here as used in Ferrari 365 GT4 2+2 Table 3 Crankshaft, Connecting Rods And Pistons. Location in Diagram: 14. Required Quantity: 1. This Ferrari part is used in more than one diagram. Click on the diagrams below to see alternative uses of this part: