Just a question would the o rings being bad cause the injectors to leak fuel into the oil?
In many cases, you can use UV dye in the fuel to find the leak. However, a trusted 6.0L tech told me that this doesn'r really work w/ the 6.0L.Yes a bad o-ring or cracked injector sleeve (or head) can cause fuel to enter the oil. The work involved in finding the bad o-ring may be more than what is needed to change them all. Actually I do not know of a way to trace down a o-ring into oil leak. You may be able to put air into the system and look at all injectors for a leak.