I am buying my first duramax the two trucks I am looking at is a 2002 ccsb lb7 4x4 with 103000 miles, it is very well maintained looks to be in good condition. I know these trucks had injectors problems, but what other problems should I look for. Should I be concerned if it has not had injectors replaced. The other truck is a 06.5 ccsb 4x4 which I know is the best of the best I have heard for Duramaxs. I know nothing about the truck my buddy owns a car lot and he got in from another car dealership. it has 98k miles what problems should I be concerned with on this truck as well. I really like the looks of the LB7 and it is in very good condition. Any help and advice would be great thanks.