Of course the engines are going to look the same. They all look the same from 2000 to 2002,just the internals and ECM programs are where the difference is. I still don't believe has an HO with the automatic... it simply doesn't exist. The window sticker doesn't prove anything,they are printed by a human being,and I have seen some goof ups.
The way to tell is by the Cummins factory horsepower rating thatis stamped on the engine data plate that is mounted on the driverside-front of the engine timing cover attached sideways.
If it's an HO then it will say 245hp,and if not it will say 235hp.
TomG, the data plate mounted on your radiator support is not the engine data plate. It is called a body buck tag. The 'tags' have all the information codes for the assembly line workers to know what options are going into the truck as it travels down the assembly line. Cummins puts data plates only on the engine.