Your search for "2001 GMC Sierra 1500 HD" revealed the following:

Bushwacker 40928-02 Image 1 GarageMAD4X4
Bushwacker GMC Sierra Boss Pocket Style Fender Flare Set (Paintable) - 40928-02 Bushwacker GMC Sierra Boss Pocket Style Fender Flare Set (Paintable) - 40928-02
Call for Pricing
Bushwacker 40118-02 Image 1 GarageMAD4X4
Bushwacker GMC Sierra Boss Pocket Style Rear Fender Flares (Paintable) - 40118-02 Bushwacker GMC Sierra Boss Pocket Style Rear Fender Flares (Paintable) - 40118-02
Call for Pricing
Bushwacker 48524 Image 2 GarageMAD4X4
Bushwacker GMC Smootback Ultimate BedRail Cap w/o Stake Pocket - 48524 Bushwacker GMC Smootback Ultimate BedRail Cap w/o Stake Pocket - 48524
Call for Pricing
Bushwacker 48527 Image 2 GarageMAD4X4
Bushwacker GMC Smootback Ultimate BedRail Cap w/ Stake Pocket - 48527 Bushwacker GMC Smootback Ultimate BedRail Cap w/ Stake Pocket - 48527
Call for Pricing
Bushwacker 48528 Image 2 GarageMAD4X4
Bushwacker GMC Smootback Ultimate BedRail Cap w/ Stake Pocket - 48528 Bushwacker GMC Smootback Ultimate BedRail Cap w/ Stake Pocket - 48528
Call for Pricing
Bushwacker 48525 Image 2 GarageMAD4X4
Bushwacker GMC Smootback Ultimate BedRail Cap w/o Stake Pocket - 48525 Bushwacker GMC Smootback Ultimate BedRail Cap w/o Stake Pocket - 48525
Call for Pricing
Fox Monotube Shock 980-24-968
Fox 2.0 Performance Series IFP Reservoir Shock Front7-9in Lift - 980-24-968 Fox 2.0 Performance Series IFP Reservoir Shock Front7-9in Lift - 980-24-968
Call for Pricing