Ok...here is what I've heard...
The 6.7 is a great motor....no issues there....the trans however is a weak link...apparently my kids friend has one and can't keep a trans in it...it's been suggested to either go back to the 4spd auto or go with a Sun coast trans which are pretty pricey...and it's a common issue with trans over heating....
the Trans blew, then was rebuilt by dealer once...blew again almost immediately..got a Chrysler reman and it blew...apparently the case distorts from heat and I guess they generate a ton of it....apparently once the case gets heated, nothing retains / fits in it properly....so I guess I'd be checking to see if the trans has been replaced, rebuilt or gone thru and if so, I'd prepare for a bit of expense as it will probably go again...and this is supposed to be a common issue with the 6spd autos.....frankly, I'm not into Dodge trucks so somewhat biased....lol...smoking deal may mean previous issues.....