I am considering purchasing a used (2003 or newer) F250 or F350 Dually ( I need to pull a 4 horse trailer with LQ). I have heard that there were/are issues with the PowerStroke. One particular F350 Dually I am looking at (2004) had to have the turbo replaced which led to numerous other problems and eventually...a new engine. What can anyone tell me about this? Has Ford been able to correct these issues? How can I tell if every needed fix has been completed on a particular truck?