Whats causes 6.0 valve train problems ??

[HAM_RADIO_MAN]

I talked to a local diesel mechanic today and all he did was bash on the 6.0 because he says they always come into his shop with valve train problems, like bent push tubes and bad rockers etc. I am seeking input on this issue to expand the community knowledge base. The causes I could suspect for these failures would be as follows.

1. Wet stacking from excess idle or low speed operation

2. Over revving and floating the valves.

3. Hydro locking the motor with fuel or coolant ( In this case I would be glad for a bent push tube vs a bent valve.)
4. What else???

In the real world how common is this problem? Do most of the valve train failures result in bent rockers and push tubes or bent valves and damaged seats. What about cam and lifter failure issues?

[NYC F-350]

You can add to that list: improper installation by an non-qualified mechanic doing some other repair.

[dazdillenger]

lol. I have a set of 6.0 heads sitting here with several seized valves due to running straight kero.

[youngstroker]

the 6.0l uses plastic clips to hold the rocker in place, kind of a cheap idea, they may be nylon, not sure only been in there once. another reason is that do to the fact that one rocker pushes on a rocker bridge, to actuate two valves, it can cause a the valves to be press down on more of an angle instead of just strait up and down and wear out the valve guides at like 180k, now i haven't really heard any problems do to this but it sounds logical to me.