5.9 Turbo Diesel, 5.9 High Output Turbo Diesel. What's the difference? And how do you identify which trucks have it and which don't?

 

For my year, the 8th digit of the VIN indicates an HO engine (C for HO and 6 for not). I think it is the 325/600 vs the 305/???. Also, look on the side of the valve cover for the Cummins engine sticker.

 

04.5 and up the HO's went away since the 600 engine is certified by CARB(Commies)

the easiest way to tell was to look on the engine data plate and see what the rated HP is.

however for 98 and up D=12 valve, 6=SO and 7=HO, D was dropped in 98.5 and 6 was dropped for the 04.5's.