I was under the impression all the Motori 6's were coming from across the pond, but I came across a line in an Allpar article that would indicate otherwise...
In the Motorhouse, where the engine assembly is completed before being mated to the chassis, the Warren Truck team had to figure out a way to manage building three different engines (a gasoline V6, a diesel V6, and a V8), with over 170 unique parts and nearly 70 parts that look and feel the same, but are different. The solution was to “kit” the parts and put them not the truck, which prevents time wasted in walking to get parts, while ensuring that the right parts are installed in the right trucks