i sold a 97 cummins with 450,000 on it and only did clutch jobs and 5th gear nut upgrade---a guy down the street has one with 750,000 and nothing on the engine has been touched-----the people with problems are the ones doing injector upgrades and turbo upgrades and they are the ones throwing out the big money and causing their own problems----keep it stock and drive the stink out of it------but if you have to have a pretty truck there is flip money to be made on it ----the engine could net $2500 and the NV4500 $1200 and crush the rest for $500....bob