My 6. 7 has been so dependable I can't see any reason to change anything on it. 290,000 miles with minor problems, pulling a trailer 95% of the time. I talk to alot of pipeliners who HATE their fords & chevys. Granted they like to sit in their trucks and let them run all day, thats just not somethimg I do with mine. Sure it would be nice to get alot better fuel milage, but the numbers I get sure beat the heck out of what my Dad got with his gas burner 454. I'm a happy camper with this dodge, I just hope I can make it to the 500k mark so I can go buy another one... (if my wife lets me):-laf