Wilwood Six-Lug Front SRP Brake System for GM Truck/SUV Iron ProSpindles, Black Superlite 6R Calipers and 12.19-Inch Rotor/Hubs (Listed 1963–1987 Applications)

Drilled/slotted 12.19-inch rotors and black Superlite 6R calipers form this six-lug front brake package. The supplied 6 × 5.50-inch hubs are for the documented Wilwood iron ProSpindle installation rather than a factory-spindle conversion. BP-10 pads are included, while braided hoses are selected separately. Confirm wheel seating and usable inside clearance as well as the bolt circle before purchase. Based in Camarillo, California, Wilwood Engineering was founded by Bill Wood in 1977. Its disc brake systems serve motorsport, street-performance and specialized applications. The range includes calipers, rotors, master cylinders, valves, fittings and brake lines, with each component chosen for its role in the complete brake installation.

Technical Details

• Manufacturer part number: 140-15944-D. Quantity: one kit for the stated axle/application.
• Mounting hardware and the specified pads are included. Spindles, master cylinder and brake booster are not supplied.
• Service caliper: Forged Narrow Superlite 6R; 6 pistons; stainless piston material. Radial mounting, black powder coat finish.
• Published piston bores: 1.75, 1.25, 1.25 inches. Supplied pad compound: BP-10.
• Caliper hydraulic inlet: 1/8-27 NPT.
• Rotor specification: 12.19-inch outside diameter × 1.10-inch thickness; SRP drilled & slotted faces. Iron construction; SRP Drilled Rotor design; published vane configuration: 32 V.
• Supplied hub assembly: Hub - Hat Mount, aluminum, bare finish.
• Wheel mounting pattern: 6 x 5.50 inches.
• Minimum nominal wheel diameter: 15 inches. The wheel must also clear the actual caliper and rotor profile in the installation drawing.
• Brake hoses are not included. Manufacturer line-kit reference(s), sold separately: 220-7056, 220-11237, 220-12168.

Fitment & Compatibility

The supplied hubs use six wheel lugs on a 5.50-inch circle. Check that interface first, then identify the matching Wilwood C10 one-piece iron Pro Drop spindles required for this front conversion. The original GM spindles will not fit, and the required ProSpindles are purchased separately. Read the model, year and option rows below to confirm the truck/SUV configuration. Compared with the original brake/spindle arrangement, the kit places the wheels 0.41 inch farther out on 1963–1970 applications, or 0.06 inch farther in on 1971–1987 applications. Include that change when assessing wheel backspacing, fender space and suspension clearance. Confirm complete hub-face seating and actual caliper clearance inside the wheels. Flexible hoses are not included and must suit the chassis fittings and full steering/suspension movement.

With over 20 years of parts and fitment experience, PMB Performance can help compare the required mounting interface with the vehicle build. Share spindle or axle measurements and wheel information before ordering if anything is uncertain.

Manufacturer documentation: Installation instructions.

Manufacturer Warning

Applicable to brake pads only: Wilwood warns of exposure to arsenic, cadmium, hexavalent chromium compounds, lead, nickel, cobalt and antimony trioxide, chemicals known to California to cause cancer or reproductive harm. More information: P65Warnings.ca.gov.