Wilwood Front Red Six-Piston Conversion for XLR (2004–2009), Corvette C5/C6 (1997–2013) and Selected GM Ridetech Hub Spindles (1962–1982), 13.06-Inch SRP Rotors

Red Superlite calipers are paired with drilled/slotted Spec-37 rotors in this GM front package. With a 13.06-inch rotor diameter and retained hubs, both the wheel template and the installed spindle identity govern selection. Based in Camarillo, California, Wilwood Engineering has designed and manufactured disc brake systems and components since Bill Wood founded the company in 1977. Its work spans motorsport, street-performance and specialized applications, with a product range covering master cylinders, calipers, brake rotors, valves, fittings and brake lines. These parts must be chosen for the requirements of the entire brake system.

Technical Details

• Manufacturer part number: 140-8921-DR
• Included pad compound: BP-10; pistons: stainless steel
• Caliper body: Forged aluminum; hydraulic inlet: 1/8-27 NPT
• Rotor surface finish: Black Electro Coat; rotors are not supplied burnished
• Rotor/hat wheel-stud clearance pattern(s): 5 x 4.5 in; 5 x 114.3 mm; 5 x 4.75 in; 5 x 120.65 mm; the existing hub/axle pattern is retained
• Hat/rotor stud-hole clearance: 0.520 in; 13.21 mm; this is not a wheel-stud thread designation
• Hydraulic hoses: not included; match the separate lines and fittings to the application
• Kit includes calipers, rotors and mounting hardware; replacement hubs and spindles are not included
• Not included: master cylinder and brake booster
• Wheel clearance: 17-inch wheels may fit; check the complete manufacturer caliper/rotor template
• Quantity: sold as one axle kit
• Service calipers: 6-piston Forged Narrow Superlite 6R; Red Powder Coat; radial mounting
• Brake rotors: 13.06 x 1.25 inches; Spec-37 Iron; SRP Drilled & Slotted; vented

Fitment & Compatibility

For 1997–2013 Chevrolet Corvette C5/C6 and 2004–2009 Cadillac XLR applications as listed. The classic 1962–1982 GM entries require the specified Ridetech hub spindles; they are not approvals for those vehicles’ original spindles. Match the exact Corvette/XLR brake package or the installed aftermarket spindle before purchase.

The 13.06-inch package retains the existing hub. Use DS502 and its wheel template to confirm clearance and bracket alignment. Hydraulic lines are separate and must suit the specific chassis; Corvette hose references must not be assumed suitable for a modified classic GM car.

The table below gives the detailed vehicle coverage; match the individual entry and each referenced note.

Manufacturer Resources

• Wilwood kit specifications and wheel-clearance information
• Installation instructions and component list

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.

Ask PMB Performance to help confirm the configuration before ordering if the vehicle has modified brakes or running gear. We have over 20 years of experience with parts and fitment; a VIN plus the installed component details gives us the best starting point.

Vehicle Applications

Application Notes

1. Universal Flexline kits available: 220-7056 (14"), 220-7699 (16") or 220-8307 (18"). Choose correct length for your application.
2. This front brake kit contains no parking-brake mechanism. Parking-brake cable selection belongs to the separate rear brake installation.
3. Line kit included (manufacturer): None
4. Front line-kit reference: 220-8176, 220-9100, , , 220-12168