I'll be shopping for a used diesel soon, and would like to know what are some signs of a problem motor and even tranny (things to look for)? For instance, it has been mentioned that the 6.0's have head bolt/gasket problems along with an EGR problem. How would I be able to tell if the truck had these problems? What color smoke (if any) should the diesel be pumping out the exhaust (what color is bad)? Any help for a potential new diesel owner would be greatly appreciated. Thanks!!