There was a tree guy in my development last week with two F750 Ford tree trucks. Both had Cummins ISX engines in them LOL
The engine in F650 and F750 is the Cummins ISB. The ISX is a class 8 truck engine.
DEF, I thought it was diesel exhaust fluid.
I own a early 04 Cummins so who am I to argue, but I will. 2004.5 had a bigger turbo, different injectors, different pistons, 3 injection events instead of two and a few other things I can't remember, but I think the heads were the same.