Shop parts and accessories that fit the 2025 GMC Sierra 3500 HD: tonneau covers, lighting, steps and running boards, suspension, exhaust, bumpers and more from the brands truck owners trust. Every part on this page is matched to the 2025 GMC Sierra 3500 HD using manufacturer fitment data. Use the vehicle selector above to narrow results by trim, cab, bed length and engine.
About 2025 GMC Sierra 3500 HD Parts & Accessories
The Sierra 3500 HD is GMC's heaviest-duty pickup, offered in single- and dual-rear-wheel versions with Denali luxury and the 6.6L Duramax. It was refreshed for 2024. 2025 Sierra 3500 HDs share fitment with 2024.
Truck Army currently carries 148 parts and accessories matched to the 2025 GMC Sierra 3500 HD using manufacturer fitment data, from brands including TrailFX, Husky Liners, Raptor Series, Bilstein, Skyjacker. New parts that fit the 2025 GMC Sierra 3500 HD are added to this page automatically.
Popular 2025 GMC Sierra 3500 HD upgrades
- Nerf Bars – Nerf bars and side steps that make getting in and out of the 2025 GMC Sierra 3500 HD easier and protect the rocker panels.
- Suspension – Leveling kits, lift kits, shocks and coilovers to fix factory rake, fit bigger tires or improve the ride of your 2025 GMC Sierra 3500 HD.
- Running Boards – Running boards and side steps sized for the 2025 GMC Sierra 3500 HD.
- Interior Protection – Custom-fit floor liners and cargo liners that keep mud, snow and spills off the 2025 GMC Sierra 3500 HD carpet.
- Toolboxes – Crossover, chest and side-mount toolboxes that keep gear secure in the 2025 GMC Sierra 3500 HD bed.
- Bed Covers – Tonneau covers that lock up tools, keep the bed dry and cut wind drag - folding, roll-up and hard covers sized to the 2025 GMC Sierra 3500 HD bed.
2025 GMC Sierra 3500 HD fitment tips
- Beds are 6 ft 9 in (standard) or 8 ft 2 in (long) - match covers, toolboxes and transfer tanks to yours.
- The 2024 refresh changed the front fascia, so many bumpers and grille guards are split into 2020-2023 and 2024+.
- 3500 dually trucks need DRW-specific fender flares and running boards.
- Factory-lifted trims like ZR2 and AT4X do not need leveling kits and may not accept standard lift kits.
- Not sure about your trim, cab or bed length? Use the vehicle selector at the top of the page, or contact us with your VIN and we will confirm fitment before you order.
Other model years: 2024 GMC Sierra 3500 HD · 2026 GMC Sierra 3500 HD
Shop all GMC Sierra 3500 HD parts
Looking beyond this year? Shop all GMC Sierra 3500 HD parts for every model year, or browse by category: Running boards & side steps · Lift & leveling kits · Shocks · Floor liners · Bed liners & bed mats · Tonneau covers · Toolboxes. See every vehicle on our Shop by Truck page.