We have a 2004 Silverado 2500HD, 4 doors: 2 suicide, 6.0 engine, 4.10 gears.
Flat bed with headache rack. 185,000 mi. 17 mpg best ( 65 mph), 13 mpg worst (stop and go traffic). We have owned it for 5000 mi.
Used to be a welders truck, I can tell where he cut off the welder and boxes. He must have taken great care of it. The interior is near perfect. ( might have come from a boneyard complete.) It starts easily, runs quietly, and pulls our 5er like it was a utility trailer. Hauls a ton of spent grain or fertilizer like it wasn't there. And it rides great while doing all of this. Previous truck was a F250.
We do so much haul and tow, a 1500 wouldn't be happy at our house.