First one actually didn't have to be replaced... spot weld fell out of oil pickup and was suckimg air so stopped running...had to pull engine to replace it
Second one an injector failed and hydro locked #8 shattered rings and scored cylinder...
Third one cracked a piston and scored cylinder...
Fourth one I actually didn't count because it was all my fault... Working late without much sleep and dropped a nut in an intake port... Fished it out and didn't realize I had actually dropped TWO nuts.... Lodged under a valve damaging piston, valve, head, and even chipping the block.
Fifth one, the air intake heater cracked apart and half of the coil went into the engine and beat up and cracked a piston...
I also didn't mention the 4r100 trans dying on me... I also didn't mention the zf6 that I swapped in dying a horrible death due to a broken cooler line.
At one point it also stranded me when the PCM suddenly died... Another time the NEW turbo came apart in less than 6 months
I have rebuilt,replaced, or otherwise had to work on nearly every component of this truck....yes I do work it hard but I've never had or even heard of any other vehicle this needy.
I have had some really horrible luck with this thing.... Most of it I chalk up as just crap luck... But they CAN break.... Like I said tho hopefully other folks good luck continues and good greif I hope mine gets better....
If you want you can search my username on PSN... It isn't all documented but about half of it is.
EDIT: btw I bought it w 289,000 and it turned over 370,000 two days ago.