Wilwood Front GT Rotor/Hub Kit, Red Six-Piston Calipers, GM Original Disc-Spindle Applications (1970–1978)

Red six-piston Superlite calipers, 12.88-inch GT slotted rotors and new hubs are the selected parts in this Wilwood GM front package. Its BP-10 pads and brackets are matched to the stated disc-spindle family. The conversion retains the suitable original upright after the required machining, rather than supplying a replacement spindle. Wilwood Engineering was founded by Bill Wood in 1977 and is based in Camarillo, California. The company designs and manufactures disc brake systems and components, including calipers, brake rotors, master cylinders, valves, fittings, and brake lines. Its product range serves motorsport, street-performance, and specialized applications, with individual components selected to match the requirements of the complete brake system.

Technical Details

• Manufacturer part number: 140-12278-R
• Type: Forged Narrow Superlite 6R Big Brake Front Brake Kit (Hub and 1PC Rotor)
• Calipers: Forged Narrow Superlite 6R; 6 pistons per caliper; Red Powder Coat; radial mounting.
• Piston bores: 1.62, 1.12, 1.12 inches; Stainless pistons. Included pad compound: BP-10.
• Rotors: 12.88-inch diameter × 1.10-inch width; GT Slotted; Iron; Black Electro Coat finish.
• Wheel mounting change from OE: +0.13 inches per side; check wheel offset and fender clearance.
• Replacement hubs: Hub - Hat Mount; Aluminum; Bare. Bearings and hub hardware are specified in the installation instructions.
• Wheel bolt circles: 5 x 4.50; 5 x 4.75 inches.
• Included: paired calipers, pads, rotors, brackets and assembly hardware, replacement hubs and bearings.
• Hydraulic flex lines are separate. Master cylinder, booster and spindles are not included; retain or select suitable matching components.
• Conditional minimum wheel diameter: 17 inches. Verify the complete clearance drawing for barrel and spoke offset before purchase.

Fitment & Compatibility

Use DS870 to evaluate the actual spindle and compare the individual year and original-brake option. The specified drilling/tapping and caliper-ear removal must be completed correctly before fitting the brackets. Allow for the outward hub offset and verify the wheel pattern and contact seating. Select brake flex lines separately, checking freedom through steering and suspension travel. The conditional minimum is 17 inches, but only the full caliper profile can establish clearance behind the wheel spokes.

Check the individual year, model, submodel and equipment conditions in the fitment table below before ordering.

Wilwood installation documents: Installation instructions.

PMB Performance has over 20 years of brake-system experience. Contact us with your vehicle, axle or spindle details and wheel measurements for fitment help.

California Proposition 65 warning, brake pads only: WARNING: This product can expose you to chemicals including Arsenic, Cadmium, Chromium (Hexavalent compounds), Lead, Nickel, Cobalt and Antimony Trioxide which are known to the State of California to cause cancer or other reproductive harm. For more information go to www.p65warnings.ca.gov.