United States, March 20 -- For nearly 80 years, Flint Assembly has been synonymous with grit, craftsmanship and trucks that go the distance. And this month, the plant reached a major milestone.Earlier this month, Flint Assembly celebrated the 16 millionth vehicle built at GM's longest-running assembly site in North America. But that's not the only moment worth celebrating: the milestone truck is powered by the 3.5 millionth Duramax diesel engine produced at DMAX, highlighting GM's shared commitment to building trucks that customers trust for the long haul.Flint Assembly brought the celebration to the plant floor as the milestone heavy-duty truck - a Lakeshore Blue Metallic Chevrolet Silverado 2500 Crew Cab LTZ - made its way through the bui...