Wilwood Black Front Superlite 6R Conversion for Bronco Drum Spindles (1966–1975), 12.88-Inch SRP Rotors

SRP drilled-and-slotted rotors distinguish this 12.88-inch Bronco front package. Black six-piston radial-mount calipers, hats and included hoses are supplied for the documented original drum-spindle installation. Disc brake system design and manufacturing are Wilwood Engineering’s focus. Bill Wood founded the Camarillo, California company in 1977; its range spans brake rotors, master cylinders, calipers, fittings, valves and brake lines for motorsport, specialized and street-performance applications. The choice of individual components depends on the complete brake system.

Technical Details

• Manufacturer part number: 140-13304-D
• Application and package: Front Brake Kits - Street Performance; Front Kits; Disc; Sold as a kit.
• Caliper assembly: Forged Narrow Superlite 6R; 6 pistons per caliper; Forged Aluminium body; Radial mount
• Piston and finish specification: Stainless pistons; Black calipers; Black Powder Coat
• Hydraulic inlet: 1/8-27 NPT
• Wheel bolt pattern(s): 5 x 5.5 in; 5 x 139.7 mm
• Stud-hole / clearance provision: 0.640 in; 16.26 mm; diameter provision, not a thread designation
• Wheel diameter starting requirement: 17 in; 431.8 mm; verify the individual wheel against the installation drawing
• Included mechanical components: Mounting hardware: Yes; hub(s): No; spindle(s): No
• Hydraulic components supplied: Master cylinder: No; brake booster: No; brake lines: Yes
• Specified pad compound: BP-10
• Separate rotor-hat specification: Aluminum; Black E-Coat; offset current exact kit and hat pages list 1.000 inch, while the linked installation parts list labels 1.300 inches; manufacturer confirmation required before relying on this dimension; part 170-13314
• Published wheel-position / hub offset: +.00 inch per side; verify against the documented spindle assembly
• Rotor dimensions: 12.88 in; 327.15 mm outside diameter; 1.25 in; 31.75 mm thickness
• Rotor construction: Spec-37 Iron; Vented; SRP Drilled & Slotted

Fitment & Compatibility

Use DS1009 to identify the Dana 30/44 drum-spindle assembly or its separately documented GM disc-conversion mounting path. These paths use different bolt and spacer arrangements; compare the installed hub, axle/drum qualifications and complete wheel profile before assembly.

Documented model groups, subject to each year, submodel and spindle/axle qualification: Ford Bronco. Application distinctions include 2700 Lbs Axle, 10" inch Drum Brakes; 3300 Lbs Axle, 11" inch Drum Brakes; 2900 Lbs Axle, 10" inch Drum Brakes.

Bronco drum-spindle applications: 1966–1973 with 2700-lb axle and 10-inch drums;1966–1975 with 3300-lb axle and 11-inch drums;1974–1975 with 2900-lb axle and 10-inch drums. Confirm the actual axle rating and spindle.

The original hub has a 3.57-inch drum-register step. The wheel must seat flush on the hub face; a separately supplied wheel spacer is needed if that step interferes.

DS1009 additionally documents a GM disc-conversion mounting path with a different bolt/spacer arrangement. Identify the actual converted spindle and use that specific assembly procedure; the drum path is not interchangeable.

The included stainless steel braided hydraulic hose kit is 220-13319, listed as 14.00 inches. Route it with adequate steering and suspension clearance.

Manufacturer References

• Wilwood exact kit specifications
• Wilwood installation instructions DS1009

PMB Performance brings over 20 years of experience to brake-component selection. Provide the actual hardware specification when the brake system has been modified.

Review the complete application table below with the year, submodel and installation qualifications above.