This Dayco Accessory Drive Belt fits your 1981 GMC K3500 5.7L V8 (Hydraulic Brake Boost Pump) and is perfect for a tune up or performance upgrade. .
Dayco Drive Belt PS and Hydraulic Brake For 1981-1982 Chevrolet P20 5.7L
Howards Cams 189425-14 Hydraulic Roller Boost Camshaft; 1955 - 1998 SBC
Howards Cams 229275-16 Hydraulic Roller Boost Camshaft; Ford 221-302/5.0L/ 351W
Meritor SP7872S Hydraulic Brake Kit Rer With Dust Boots, Hydraulic Sea for PAI
2011-12 Ford F150 EcoBoost Vacuum Assist Valve Brake Boost Pump 3.5L A426K F-150
Wilwood Complete Brake Boost Removal Kit - Silver For Honda Acura