Install a set of BBK performance underdrive pulleys and see an average of 8-15 additional horsepower over the stock pulleys. Under drive pulleys increase engine output by reducing the draw of the engines accessories by slowing them down and reducing the HP they use. Additional and significant performance improvements can be seen by reducing the weight of the pulley versus the original pulley which is why we recommend the BBK CNC Machined billet aluminum pulley kits for maximum horsepower gains. ALL BBK pulley kits are designed as direct bolt on replacements for the current factory pulleys and retain full cooling and charging characteristics. BBK under drive pulley kits are vehicle specific and each kit comes with complete installation instructions and allow the re-use of existing serpentine belts. Power-Plus Series? Underdrive Pulley System; CNC Machined Billet Aluminum; 3 Piece Kit; Incl. Crank Pulley/Water Pump Pulley/Alternator Pulley/All Required Hardware; Chevrolet: Blazer 87 - 87 Custom Deluxe / Silverado, Chevrolet: C10 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: C10 Suburban 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: C20 85 - 86 Base / Cheyenne / Custom / Scottsdale / Silverado, Chevrolet: C20 Suburban 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: C30 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: Camaro 85 - 87 Berlinetta / Iroc-Z / LT / Sport / Z28, Chevrolet: Caprice 85 - 87 Base / Classic / Classic Brougham / Classic LS Brougham, Chevrolet: Impala 85 - 85 Base, Chevrolet: K10 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: K10 Suburban 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: K20 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: K20 Suburban 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: K30 85 - 86 Custom / Scottsdale / Silverado, Chevrolet: K5 Blazer 85 - 86 Custom / Silverado, Chevrolet: Monte Carlo 85 - 87 Base / LS / SS, Chevrolet: R10 87 - 87 Custom Deluxe / Scottsdale / Silverado, Chevrolet: R10 Suburban 87 - 87 Custom Deluxe / Scottsdale / Silverado, Chevrolet: R20 87 - 88 Custom Deluxe / Scottsdale / Silverado, Chevrolet: R20 Suburban 87 - 87 Custom Deluxe / Scottsdale / Silverado, Chevrolet: R30 87 - 87 Custom Deluxe / Scottsdale / Silverado, GMC: C1500 85 - 86 Base / High Sierra / Sierra Classic, GMC: C2500 85 - 86 Base / High Sierra / Sierra Classic, GMC: C3500 85 - 86 Base / High Sierra / Sierra Classic, GMC: K1500 85 - 86 Base / High Sierra / Sierra Classic, GMC: K2500 85 - 86 Base / High Sierra / Sierra Classic, GMC: K3500 85 - 86 Base / High Sierra / Sierra Classic, GMC: R1500 87 - 87 Base / High Sierra / Sierra Classic, GMC: R1500 Suburban 87 - 87, GMC: R2500 87 - 87 Base / High Sierra / Sierra Classic, GMC: R3500 87 - 87 Base / High Sierra / Sierra Classic, Pontiac: Firebird 85 - 87 Base / S/E / Trans Am