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Choose your trim in My Garage to confirm exact fit.
Exact-fit parts for the 2021 GMC Sierra 3500 HD Base.
Standard Motor Products
Part # SC840
$36.28
Standard Motor Products
Part # HLS1785
$51.96
Denso
Part # 4717
$12.03
Standard Motor Products
Part # PSW149
$75.33
Holstein Parts
Part # 2IGC0538
$43.67
Standard Motor Products
Part # HLS1787
$53.92
Standard Motor Products
Part # DWS2050
$52.69
Standard Motor Products
Part # HP4485
$32.52
Dorman
Part # 99446ST
$132.81
Delphi
Part # AF10682
$99.33
Walker Products
Part # 235-1893
$18.62
Standard Motor Products
Part # S2936
$52.67
Walker Products
Part # 924-6009
$120.71
Standard Motor Products
Part # SC838
$31.82
LUK
Part # GATK6L90
$57.08
Delphi
Part # SS12444
$26.82
Collision
Part # GM1762112
$77.88
Delphi
Part # SS11936
$22.96
Collision
Part # GM1095228C
$122.92
Bosch
Part # 96307
$8.12
This page groups parts listed for the 2021 GMC Sierra 3500 HD Base. Some products fit every trim, while others depend on submodel, engine, drivetrain, or brake package. Use your trim in My Garage or the product page fitment check to confirm exact fit.
We offer a wide selection of wiring & electrical parts for the 2021 GMC Sierra 3500 HD Base. This page narrows the catalog to the year, make, and model; use your trim on product pages to confirm exact fit when a part only fits certain submodels.
We carry parts from trusted brands including Standard Motor Products, Dorman, Walker Products, Collision, and Delphi, plus many more. Filter by brand to find your preferred manufacturer.
Most in-stock items ship within 1-2 business days. Shipping rates are calculated at checkout based on your location.
Warranty coverage varies by manufacturer but typically ranges from 1 year to lifetime. Each product page includes specific warranty information from the manufacturer.
