Wilwood Rear Brake System, 1958–1964 Oldsmobile / Pontiac Housing Ends, 2.81-inch Offset - GT Slotted Rotors in 12.88-inch Diameter, Red FNSL4R

Red FNSL4R calipers pair with GT slotted Spec-37 rotors in this rear kit for the specified Olds/Pontiac ends. The included aluminum hats and drum parking mechanism support a measured 2.81-inch axle offset; hoses and cable hardware remain separate installation choices. Wilwood Engineering designs and manufactures disc brake systems and components, including calipers, brake rotors, master cylinders, valves, fittings and brake lines. Bill Wood founded the company in 1977; its Camarillo, California operation serves motorsport, street-performance and specialized applications. Each component must be chosen for its role within the complete braking system.

Technical Details

Rotors and mounting dimensions

• Rotors: 12.88 in; 327.15 mm diameter x 1.10 in; 27.94 mm thick; vented Spec-37 Iron
• Friction faces: GT Slotted
• Rotor finish: Black Electro Coat
• Internal vanes: 48 curved
• Hats: aluminum; Black E-Coat; 1.950-inch hat offset
• Rotor/hat wheel-stud clearance patterns: 5 x 4.5 in; 5 x 114.3 mm; 5 x 4.75 in; 5 x 120.65 mm; 5 x 5 in; 5 x 127 mm
• Hat wheel-stud clearance holes: 0.520 / 0.520 / 0.520 in, corresponding to the listed hat patterns

Kit contents and separate parts

• Manufacturer part number: 140-9224-R
• Supply: one kit with brake components for both sides of the rear axle
• Mounting hardware: included
• Hubs: not included
• Spindles, master cylinder and brake booster: not included
• Hydraulic hoses: not included
• Required axle housing end: Olds/Pontiac
• Axle offset: 2.81 in; 71.37 mm
• The supplied internal-shoe parking brake operates independently of the four-piston service calipers.

Calipers and friction components

• Calipers: Forged Narrow Superlite 4R; 4 pistons per caliper
• Caliper finish: Red Powder Coat
• Body construction: Forged aluminum
• Piston material: stainless
• Caliper mounting: radial
• Hydraulic inlet: 1/8-27 NPT
• Included pad compound: BP-10
• Listed piston bore sizes: 1.12 / 1.12 in

Fitment & Compatibility

Selection is determined by the 1958–1964 Oldsmobile/Pontiac housing-end pattern and a measured 2.81-inch axle offset, including modified vehicles fitted with those ends. The vehicle entries in the table below do not establish stock rear-axle compatibility: a Ridetech front-spindle description does not identify the rear housing end. Verify flange, bearing, register and shock clearance using DS-534 and the axle-offset worksheet. Parking cables and hydraulic lines are purchased separately; universal cable kit 330-9371 is an application-dependent option. Nominal minimum wheel diameter: 17 in; 431.8 mm. Compare the actual wheel barrel and spokes with the linked clearance drawing; diameter alone does not establish fit.

Installation documents

• Installation instructions
• Technical bulletin

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.

With over 20 years of brake-system and restoration experience, PMB Performance can help you review the application, wheel clearance and remaining parts for the installation.

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. Universal Parking Brake cable kit, may require modifications to cable or vehicle to install.
3. Line kit included (manufacturer): None