The CP4.2 to CP3 conversion is relatively straightforward (as much as it can be when accessing an injection pump sitting at the very front of a 6.6L Duramax LML engine’s valley).

When we began this journey, we wanted to present to you a CP3 injection-pump conversion and a Wehrli Custom Fabrication compound-turbocharger kit installation o ...

If your truck is powered by an LML Duramax or 6.7L Cummins, you could replace the CP4 pump by using a CP3 conversion kit from S&S Diesel Motorsport.