Wilwood Oldsmobile/Pontiac Rear Dual-Caliper Drag Brake Conversion, 2.81-Inch Offset, Half-Inch Studs and Super Alloy Rotors

Use dual XRD rear calipers on the documented Oldsmobile/Pontiac axle flange. Confirm half-inch studs, 2.81-inch offset and separate hydraulic circuits. The wheel-end assembly is selected by its measured housing-end interface and racing hydraulic arrangement. Wilwood Engineering was established in 1977 by Bill Wood and is based in Camarillo, California. Disc brake systems and components are its focus, from brake rotors and calipers to master cylinders, valves, brake lines and fittings. Its work spans motorsport, street-performance and specialized applications, with the complete brake system determining the correct individual components.

Technical Details

• Axle stud requirement: 1/2-inch diameter
• Hydraulic flexlines: Not included; supply suitable hoses and fittings separately
• Mounting hardware: Included; verify the installed fastener engagement
• Not included: spindles, wheel hubs, master cylinder or brake booster
• Manufacturer part number: 140-17878-D
• Brake assembly: rear conversion kit; Sold as a kit.
• Calipers: Forged XRD Lug Mount; 4 pistons per caliper; Type III Anodize
• Caliper mounting: Lug
• Included pad compound: BP-28
• Piston material: Stainless
• Hydraulic caliper inlet: 1/8-27 NPT
• Rotor dimensions and construction: 11.25 × 0.35 inches; Super Alloy; Drilled
• Wheel-size reference: 15 in; the complete wheel-clearance drawing determines fit
• Axle mounting interface: Olds/Pontiac; measured axle offset 2.81 in
• Rotor / hat axle-flange drilling: 5 X 4.50; 5 X 4.75; 5 X 5.00 inches; this does not change the retained hub or axle wheel pattern

Fitment & Compatibility

This dual-XRD package is selected for a measured 1958–1964 Oldsmobile/Pontiac rear housing end, 2.81-inch axle offset and half-inch wheel studs. Four calipers are used across the rear axle, so establish the intended hydraulic connections and space for both calipers at each rotor. Follow DS-1609 for bearing retainers, axle registration and dynamic hat assembly. The 11.25-inch drilled Super Alloy rotors use snap-ring retention in the lug-drive hats; those holes do not change the axle wheel pattern. Provide flexlines separately. Chevelle, 442, Beaumont, Camaro and Apollo rows below do not confirm the installed rear axle and require measured verification.

Wilwood product specifications · Wilwood installation and compatibility information · Axle measurement worksheet · Wilwood installation and compatibility information

Before purchase, send PMB Performance the actual housing flange, axle offset, rotor registration and parking or hydraulic arrangement. Our over 20 years of parts and fitment experience helps identify the installation details that need to be checked.

Manufacturer warning — brake pads only: WARNING: Cancer and Reproductive Harm. www.P65Warnings.ca.gov.