It is a truck, pickup, kind of. It has a truck bed. But it is not a separate box, and the frame, chassis are still based on the 130" wheelbase Suburban with independent rear suspension, not 145" WB with leaf springs like a crew cab pickup. The Suburban itself is often referred to as a truck, as it is a traditional body on frame and designed/built more like a truck. The 5.3L V8 is the same/similar to the Silverado/Sierra, as is the transmission and maybe axles. The hood, headlights, etc are Suburban, not Sierra.
Wiki. Classified for licensing by your DMV as a truck. GM may even call it a truck.
