2025 Denali 3500. With a 6.6l v8 engine, advanced trailering system, and a plush in. Adaptive cruise control with trailering assist, previously standard on the 2024 at4x and denali ultimate trim levels, now comes on the at4 and denali trims as well.

The 2025 gmc sierra hd is available in seven trim levels in the 2500 hd configuration, including pro, sle, slt, at4, denali, at4x, and denali ultimate, while the 2025 gmc sierra hd in the 3500. Complete specs for 2025 gmc sierra 3500hd.