Whats the difference between the 2004 and 2004.5 cummins.

 

20 HP and 45 FT/LB of torque.

 

catalytic converter, more hp and torque, quieter, little less mpg.

 

Bigger housing on the Turbo along with an electronic wastegate. 4'' exhaust from the turbo all the way back, but including the Cat Converter.

A little bit easier to make big power due to more options in power boxes, downloaders etc......and a little bit more power in the ECM computer.

 

Oil cooling jets for the pistons and i think sodium filled valves

NOTE: I think the HO's had the jets before 04.5