The GM 6.5L diesel injection pump fuel delivery is fine tuned with a resistor in the PMD. The resistors range in number from one to nine. The number nine will deliver the highest fuel delivery. If no resistor is used, the pump will default to the number five. We recommend using the number nine resistor to give you that little extra performance.
Note: Stanadyne changed the connector between the wiring harness and the PMD when they updated their PMD. Use this resistor with the new gray colored Stanadyne PMD's.