i agree with RASPY, unless highly modifyed (more than a chip kids) i would say that cummins wasnt lying when they built it for no wait to shut off. only years i see a threat is 02 and older with the exh. manifolds cracking. i mean they started building these truck for moms and every day joe shmoe to get in drive and shut off like a normal rig. i will after a freeway run or so wait 45sec then shut off, but they wouldnt have built the truck with that motor unless every day people can use it (even the ones with out common sense.

 

Hot shutdown isnt really too hard on the engine, it is the turbo that is the concern. 350deg preturbo is plenty cool enough. The lower the temperature gets the smaller the difference between pre and post turbo.