I wouldn't be concerned with the mileage on the diesel. The Cummins 6.7L is a medium duty rated diesel (250k miles before rebuild). However, I would make sure that it is in good running condition and that there are no known problems with the turbo or injectors. 2007-2009ish 6.7L Cummins had some problems with the DPF (diesel particulate filters) getting filled up fast and if not properly taken care of might require a new one to be installed in short order. A lot of people were removing (deleting) the DPF (diesel particulate filter and EGR (exhaust gas recirculator) systems. It wouldn't pass a smog inspection in CA if it's missing. If you are buying it from a Dodge dealer then ask them for the options report and warranty record to see if anything was done under warranty. If you're not buying it from a Dodge dealer then PM me the VIN and I'll pull it for you and send it back. That way at least you'll know easily what rear axle ratio is in that truck amongst other things. Diesel engines are a little bit more expensive to work on should somthing go out so I would consider the purchase of an extended service contract as well if it fits the budget.
