Best Seller | 2020-2024 GMC Sierra 3500 HD Nerf Bars - Autopart Premium GMC Sierra 3500 HD Nerf Bars. Brand: Autopart Premium. Fits Years: 2020, 2021, 2022, 2023, 2024, 20, 21, 22, 23, 24. Step Nerf Bar -- Extended Cab Pickup; 6.5 Inch Textured Black Steel Rattler Running Board, Fit Extended Cab/Double Cab, Not fit Crew... ... more 2020-2024 GMC Sierra 3500 HD Nerf Bars - Autopart Premium GMC Sierra 3500 HD Nerf Bars. Brand: Autopart Premium. Fits Years: 2020, 2021, 2022, 2023, 2024, 20, 21, 22, 23, 24. Step Nerf Bar -- Extended Cab Pickup; 6.5 Inch Textured Black Steel Rattler Running Board, Fit Extended Cab/Double Cab, Not fit Crew... Partsgeek.com | | $259.95 FREE shipping go to store |