Wilwood Rear Super Alloy Drag Brake Kit, Olds/Pontiac 2.81-Inch Offset, Large-Stud, Chevrolet/Oldsmobile/Pontiac/Buick Chevelle/442/Beaumont/Camaro/Apollo (1964–1974)

This Wilwood rear drag package uses large-stud lug-drive hats with the Olds/Pontiac housing flange and 2.81-inch offset. Single four-piston Dynapro calipers clamp 11.44-inch drilled Super Alloy rotors with BP-28 pads. The axle-end dimensions establish the mounting; the listed vehicle models and their front suspension options do not by themselves prove a rear-axle fit. 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 for motorsport, street-performance, and specialized applications.

Technical Details

• Manufacturer part number: 140-12550-D
• Type: Dynapro SA Lug Drive Dynamic Rear Drag Brake Kit
• Calipers: Dynapro Lug Mount; 4 pistons per caliper; Type III Anodize.
• Caliper bore sizes: 1.75, 1.75 inches. Piston type: Stainless.
• Included pad compound: BP-28.
• Rotors: 11.44-inch diameter × 0.35-inch thickness; Drilled; Super Alloy; Plain surface; solid, unvented.
• Rear housing end: Olds/Pontiac.
• Required axle flange offset: 2.81 inches.
• Wheel bolt circles: 5 x 5.00; 5 x 4.75 inches.
• Included: paired calipers, pads, rotors, mounting brackets and assembly hardware, rotor hats.
• Hydraulic lines and fittings selected separately. No master cylinder, booster or spindles are supplied.
• Conditional wheel screening size: 15 inches. Use the installation clearance diagram to verify the actual barrel and spoke profile.
• Axle-flange limit: 6.29-inch maximum outside diameter with the specified 0.050-inch × 45-degree chamfer. Match the register and stud configuration to the exact installation drawing.

Fitment & Compatibility

Confirm permitted wheel-stud size with Wilwood before ordering: the product note says 0.64 inches, while DS912 specifies 0.68-inch studs. The hat's 0.700-inch hole is a clearance dimension and must not be treated as the stud diameter. Measure the housing pattern, register and offset, and verify the complete rear application. Hydraulic connections and wheel clearance require separate checks for the drag-racing installation.

Match the individual model, year, submodel and brake configuration in the fitment table below.

Wilwood installation documents: Installation instructions; Technical bulletin.

PMB Performance has over 20 years of brake-system experience. Contact us with your vehicle details and installed brake hardware for help confirming the correct arrangement.

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.