My truck is a 2004.5. It had factory 4" exhaust and it has a lift pump mounted in the tank. On the valve cover it says advertised HP 325 HP. So obviously its got to be the 325HP600 motor right?anything else to look for?

 

If it had a catalytic converter, it is an 04.5. I see it has been replaced. The 325/610 is also a clue. Yes, it is an 04.5.

 

look at the build date on the drives door, anythink built after jan1 of 04 is an 04.5 and won't be the triple nickel engine.

 

so mine is a 325HP 610 or 325 HP 600? it did have a cat converter

 

You have the 325/600. The 610 come out in 05.

 

Do you have your window sticker? On mine under the line item "5.9L Cummins HO Turbo Diesel Engine" it also has "Cummins 600 Turbo Diesel"