Remanufactured DS4 Injection Pump - With ULSD Upgrade

All computer operated 6.5L diesels had the DS4 injection pump starting in 1994.  If you are unsure of what model you need, please read the ID # off your existing pump or contact us before ordering.  All model numbers other than 5068 are compatible with a 5521 replacement. What makes this pump stand out from the rest? Tier 2 Rebuild: This pump is our Tier 2 rebuild, a step above the rest, featuring: Stanadyne ULSD upgrade kit installed (see below) OEM Stanadyne authorized rebuild quality. No substitutes. No aftermarket parts Calibrated to OEM 5521S Specifications New Timing Stepper Motor We only use the best components available including the genuine Stanadyne ULSD (Ultra Low Sulfur Diesel) upgrade kits ($175 value). The "S" at the END of the model number indicates a pump has been updated (5521S, 5068S, etc).  An "S" before the model number does not mean a pump has this update.  When comparing our pumps to others, keep this in mind because it's a key differentiating feature. The f