 The 6.0L Diesel has been nothing but an expensive problem. Can't keep fuel injectors in it.  Ford does not care about the problem.  I know of many others who own the 6.0L diesel and have the same problems.  If you pull a trailer or carry heavy loads, the 6.0 can't handle it.  If you are a "Weekend Cowboy" and just ride around in the truck, it might be ok.