Looking to upgrade from my 95 cummins to a 2006 4x4 quad cab short bed automatic with the 5. 9. Any particular areas I should pay attention to when looking at these trucks besides the normal signs of good maintenance? I want a 5. 9, and found a few 2006 trucks with the options I like. All of the trucks I have been looking at are in 40k - 60k mile range