Wilwood Large-Stud Dual Rear Drag Brake Kit for Symmetrical Lamb/Mark Williams Ends

Four hydraulic calipers across the rear axle define this Wilwood dual Dynapro drag package. Each wheel carries two separate four-piston units with 1.38-inch bores, operating on a single 11.44-inch drilled Super Alloy ring. The lug-drive hats and brackets suit the specified Lamb/Mark Williams symmetrical housing end, 2.81-inch flange offset and large-stud arrangement. Selecting this configuration requires matching both the mechanical axle dimensions and the hydraulic needs of the four-caliper layout. 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: 140-12557-D
• Type: Dynapro Dual SA Lug Drive Dynamic Rear Drag Brake Kit
• Calipers: Dynapro Lug Mount; 4 pistons per caliper; Type III Anodize.
• Caliper quantity: four total, arranged as two four-piston calipers at each rear wheel.
• Caliper bore sizes: 1.38, 1.38 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: Symmetrical End.
• Required axle flange offset: 2.81 inches.
• Wheel bolt circles: 5 x 5.00; 5 x 4.75 inches.
• Included: four rear 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 the actual stud specification with Wilwood before ordering. DS919 identifies 0.68-inch studs, but the product note says 0.64 inches; the hat has 0.700-inch clearance holes, a separate measurement. Use the axle worksheet to record upper/lower horizontal bolt spacing, vertical spacing, center register and wheel-side flange offset. Check those against the bracket and hat drawings before the solid rotor ring is assembled to its dynamic mount. The four supplied calipers require a hydraulic plan appropriate to the completed drag chassis, with hoses and fittings selected separately. Compare barrel and spoke clearance at both calipers on each wheel, rather than checking one side of the rotor only.

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.