Wilwood Engineering has released a new lineup of bolt-on big brake kits for the 1971–1991 Chevrolet K5 Blazer 6-lug 4×4 platform. The kits cover four front axle sizes and three rear axle sizes, with front rotors ranging from 12.19 to 15.00 inches and rear options up to 14.00 inches. Builders can retain a factory-style internal drum parking brake or upgrade to Wilwood’s Electric Parking Brake (EPB) system. Additional fitments include Chevy K10, GMC K15, and K1500 platforms.
Highlights
- Four front rotor sizes (12.19–15.00 inches) and three rear sizes with EPB or drum parking brake options for 1971–1991 K5 Blazer 6-lug platforms
- Superlite FNSL6R and Aerolite AERO6 six-piston calipers serve front applications; Dynalite and four-piston Superlite and Aerolite calipers handle the rear
- Kits also fit rear end swaps to the New Big Ford 9-inch differential with a 2.50-inch offset
- MSRP starts at $1,539.65 for rear kits and $3,467.51 for front kits
Kit Overview and Platform Coverage
The kits are designed as complete bolt-on upgrades for traditional non-ABS setups. They fit both OE drum and disc brake spindles. Wilwood stated the kits increase thermal capacity to support upgraded wheels, tires, and suspension components across highway, towing, commercial, and off-road driving conditions.
Two rear kit configurations are also available for vehicles using the New Big Ford 9-inch differential with a 2.50-inch offset. Rotor options include E-coated GTB slotted and SRP drilled-and-slotted configurations. All rotors use Wilwood’s proprietary Spec37 iron alloy, which the company said was developed to withstand high temperatures while resisting distortion and cracking. Rotors feature up to 72 internal cooling vanes.
Front Axle Caliper and Rotor Configurations
Front axle kits use six-piston forged aluminum calipers in two series:
- Superlite FNSL6R: Available with 12.19-inch x 1.10-inch and 12.88-inch x 1.25-inch rotors. Radial-mount design. Requires a 15/16-inch bore master cylinder (P/N 260-18184) when used with the factory brake pedal and vacuum booster.
- Aerolite AERO6: Available with 14.00-inch x 1.25-inch and 15.00-inch x 1.25-inch Spec37 rotors. Features a rigid center bridge for reduced deflection under load.
Front kits require enlarging wheel stud holes to 39/64-inch (0.609-inch) diameter. Stainless steel Flexline hose kits are available separately based on vehicle configuration.
Rear Axle Configurations and Parking Brake Options
Rear kits use four-piston calipers across three series. Each offers a choice between internal drum parking brake retention and Wilwood’s EPB system. The EPB package includes a dedicated ECU, wiring harness, remote switch, and connectors.
- Dynalite FDLI: Four-piston forged aluminum calipers starting at 3 lbs. Paired with 12.19-inch x 0.81-inch rotors.
- Superlite FNSL4R: Four-piston radial-mount calipers with 12.88-inch x 1.10-inch Spec37 rotors. Also available for the Big Ford 9-inch differential swap.
- Aerolite AERO4: Four-piston calipers with 14.00-inch x 1.10-inch Spec37 rotors. Also available for the Big Ford 9-inch differential swap.
Brake Pads and Finish Options
Every kit ships with Wilwood’s BP-10 street performance brake pads, which the company described as providing smooth and consistent response with long wear. Alternative pad compounds are available to suit specific driving demands.
All calipers are offered in gloss red or black powder coat as standard. Additional color options are available at extra cost. Each kit includes caliper brackets and premium-grade installation hardware.
Pricing and Availability
Wilwood listed the following starting MSRP pricing:
- FNSL6R 12.19-inch front kit: $3,467.51
- FNSL4R 12.88-inch rear kit with EPB: $1,539.65
- AERO6 15.00-inch front kit: $3,820.29
Pre-sale data sheets with modification requirements and application recommendations are available through wilwood.com. For technical assistance, contact Wilwood Engineering at [email protected] or call (805) 388-1188.
Subscribe to The BRAKE Report. Get free sample chapters.
