Factory Spec M113K Supercharger Pulley Bolt, 12.9 Hardened Tool Steel with Anti-corrosion Black Anodized coating.
You can use this on Any M113K motor with Factory Supercharger.
If you are pairing with Factory style Clutched Pulley, use both Bolt AND Washer.
If you are pairing with Fixed style Pulley, use ONLY Bolt.