I see Duramaxes frequently when I acquire my Cummins junk.
Problem is, I can't justify buying a longblock Duramax, with no cores (Injectors, Turbo, pump) for $500-$1000 when I have no place to go with them.
I'm sitting on a very complete 6.0 Ford shortblock that I can't even get an offer on and 7.3s are almost a waste of time.
So, I'm likely to just continue as a scrounger of Cummins cores, which is by far easier to acquire and just as much a money maker.
Mark.