Trail Tough did a Sammy called the "Crustacen" that had a kind of dually set up.



I've seen some full size rigs with dually setup, but not in a crawl setup.  Problem is the fact that the sidewalls of the tires would rub and disentegrate.  Seen may rigs with duallys run tires to wide and they would eat there sidewalls up.  Yeah, it looks cool!