You see, for the vast majority of Chevy's truck history, the "heavy-duty" trucks consisted of a different chassis code and greater payload and towing capacity. There weren't really any styling differences. This is more understandable considering that before the AK series Chevy trucks introduced in 1941 (represented by a 1942 model in the gallery above), trucks were basically still beefed up cars. That AK pickup was the first Chevy truck design that diverged from the cars.
With these trucks, the only visual indicator of being a "heavy duty" truck would typically be a badge telling how capable the truck was. And we put "heavy duty" in quotes because, while that's how we refer to the heavy-load versions of full-size pickups, they're technically still light-duty. The next size up is medium-duty, which today is represented by vehicles such as the recently added Silverado 4500 and up. We digress, though. Early on, the "heavy-duty" trucks had a classification of 3600, 3800, Series 36 or Series 38. When the trucks adopted the long-running C/K model, the heavier duty trucks had the 20 and 30 series designations. More attention was paid at the time to make different model years and trims unique. And one of those trims was the Silverado, which wasn't the actual model name until the 1990s.
It also wasn't really until the 21st century that the heavy-duty Silverados began to get some styling differentiation. And typically, that just meant the addition of a slightly taller hood. The grille later started getting extra slots between the chrome bar across the middle. The most visually distinct heavy-duty Silverado so far has been the 2017 and newer model with the Duramax diesel V8. That's because it added a hood scoop in addition to the bigger hood and slightly more menacing grille.
The new Silverado HD's fierce front end isn't the only major departure in Chevy truck design. Only the roof is shared with the regular-duty 1500. That means the rest of the sheet metal is unique. Until this new model, the cabs, beds, doors and more were pretty much the same between 1500 and HD Silverados.
While the 2020 Silverado HD does mark a new era for heavy-duty Chevy truck design, it does follow a path started by rivals Ford and Ram. Ford started giving its Super Duty pickups unique cabs and front ends in the early 2000s that distinguished them as something different from a regular F-150. Ram began to separate the 1500 and 2500 a few years later, and the latest model shows the most differences yet. It will be interesting to see how this new Silverado HD fares in the market.