Wilwood Front Six-Lug GT Hub System for GM Truck/SUV Iron ProSpindles, 13.06-Inch Rotors with Black Superlite Six-Piston Calipers (Listed 1963–1987 Applications)

This black Superlite 6R front conversion uses the larger 13.06-inch GT rotor ring with separate hats and six-lug aluminum hubs. BP-20 pads accompany the slotted rotors. It requires Wilwood's one-piece iron Pro Drop spindles on the listed GM truck/SUV application, with a 6 × 5.50-inch wheel pattern. Account for the published change in wheel position before choosing final wheel backspacing. Founded by Bill Wood in 1977 and based in Camarillo, California, Wilwood Engineering designs and manufactures disc brake systems for motorsport, street-performance and specialized applications. Its calipers, brake rotors, master cylinders, valves, fittings and brake lines are selected to suit the complete braking system.

Technical Details

• Manufacturer part number: 140-15945. Quantity: one kit for the stated axle/application.
• Minimum nominal wheel diameter: 17 inches. The wheel must also clear the actual caliper and rotor profile in the installation drawing.
• Rotor specification: 13.06-inch outside diameter × 1.25-inch thickness; GT slotted faces. Spec-37 Iron construction; GT 48 Curved Vane design; published vane configuration: 48 CV.
• Rotor hats: aluminum, black e-coat finish; Big Brake Hat - Flared Bell. Hat offset: 1.380 inch.
• Supplied hub assembly: Hub - Hat Mount, aluminum, bare finish.
• Wheel mounting pattern: 6 x 5.50 inches.
• 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-20.
• Caliper hydraulic inlet: 1/8-27 NPT.
• Brake hoses are not included. Manufacturer line-kit reference(s), sold separately: 220-7056, 220-11237, 220-12168.
• Mounting hardware and the specified pads are included. Spindles, master cylinder and brake booster are not supplied.

Fitment & Compatibility

Start with the installed spindle: this front system requires the specified Wilwood C10 one-piece iron Pro Drop version. Factory GM spindles are excluded. The six-lug hubs use a 6 × 5.50-inch wheel pattern, so confirm the wheels as well as their internal space around the 13.06-inch rotor and caliper. Wheel position changes from the stock brake/spindle combination by 0.41 inch outboard on 1963–1970 applications, or 0.06 inch inboard on 1971–1987 applications. Use that change when deciding backspacing and body clearance. The table below contains the distinct GM truck/SUV year/model entries and spindle conditions. Spindles and braided hoses are separate purchases; select hose fittings and length to suit the chassis.

PMB Performance has over 20 years of experience working with parts and fitment details. Provide the actual brake hardware, mounting dimensions and wheel measurements when requesting help with this conversion.

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.