2003 - 2007 5.9L Cummins
From 2003 to 2007, Cummins offered two different turbochargers for its 5.9L engine. A Holset HE341CW was used in 2003 featuring a mechanically controlled internal wastegate that holds higher than stock boost pressures.
However, to better comply with emissions regulations, the 2004.5 to 2007 engines came with Holset’s HE351CW. This turbocharger is similar to the HE341CW but the wastegate is electronically controlled. This new turbocharger allows for a noticeable boost in performance and lowered emissions output.