Wilwood Rear Big Ford Old-Style GT Package with Polished Calipers, 2.36-Inch Offset & 12.88-Inch Rotors

The polished-caliper GT configuration uses 12.88-inch slotted rotors on old-style Big Ford axle ends. The 2.36-inch offset and original housing flange dimensions establish fitment; caliper appearance does not change the mounting requirements. Calipers, brake rotors, master cylinders, valves, fittings and brake lines are all part of Wilwood Engineering’s range of disc brake systems and components. The Camarillo, California company was founded in 1977 by Bill Wood and designs and manufactures these products for motorsport, street-performance and specialized applications. Compatibility with the complete brake system determines the appropriate component choice.

Technical Details

• Manufacturer part number: 140-9217-P
• Service calipers: 4-piston Forged Narrow Superlite 4R; Polish; radial mounting
• Brake rotors: 12.88 x 1.10 inches; Spec-37 Iron; GT Slotted; vented
• 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; 5 x 5 in; 5 x 127 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
• Required axle offset: 2.36 inches; measure from the axle flange to the housing flange as shown in the instructions
• Parking brake: internal drum/shoe assemblies included; cable, clevis and control hardware are separate
• 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

Fitment & Compatibility

Choose this polished GT package for an old-style Big Ford housing that measures 2.36 inches at the axle offset. The supplied retainers and parking backing plates follow DS527, including the bearing and mounting-hole requirements. A 2.80-inch adapter is provided for the 3.06-inch hat bore. Axle flange diameter cannot exceed 6.61 inches with the required chamfer. Brake plumbing and parking cables remain separate purchases when needed. Confirm the actual rear hardware on any listed vehicle before treating its name as a fitment match.

Use the fitment table below to confirm the exact model, year, trim and all numbered application notes.

Adjust and test the mechanical parking brake as directed. Cable routing, tension and shoe adjustment affect its holding ability; do not rely on an untested parking brake alone to secure the vehicle on a slope.

Manufacturer Resources

• Wilwood kit specifications and wheel-clearance information
• Installation instructions and component list
• Axle-offset measurement worksheet

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 parts and fitment experience, PMB Performance can help review the intended brake installation. Provide your VIN, wheel measurements and any modified axle or spindle details when asking about compatibility.

Vehicle Applications

Application Notes

1. Line kit included (manufacturer): None