Wilwood Rear 12.19-Inch GT Brake Kit for GM Six-Lug 4x4 (1971–1991), Red Dynalite & Internal Parking

The red GT-slotted rear kit combines compact Dynalite Internal service calipers with 12.19-inch rotor/hat assemblies. It is built around the specified GM flange and 2.46-inch offset, with a mechanical drum-in-hat parking brake included. Based in Camarillo, California, Wilwood Engineering has designed and manufactured disc brake systems and components since Bill Wood founded the company in 1977. Its work spans motorsport, street-performance and specialized applications, with a product range covering master cylinders, calipers, brake rotors, valves, fittings and brake lines. These parts must be chosen for the requirements of the entire brake system.

Technical Details

• Manufacturer part number: 140-18158-R
• Rotor specification: Iron, GT Slotted, vented; 12.19 x 0.81 inches
• Caliper specification: 4-piston Forged Dynalite Internal in Red Powder Coat; lug mount
• Included service pad compound: BP-10; Stainless pistons
• Caliper body material: Forged aluminum
• Hydraulic inlet: 1/8-27 NPT
• Rotor/hat wheel-stud clearance pattern(s): 6 x 5.5 in; 6 x 139.7 mm; match the installed hub/axle pattern
• Housing/flange application: K5 Blazer / K10
• Required axle offset: 2.46 in; 62.48 mm
• Parking brake: included internal drum/shoe assembly; cable and clevis hardware are not included
• Hydraulic brake hoses: not included; select the correct application-specific lines/fittings
• Wheel clearance: 15-inch wheels may fit; verify the manufacturer’s complete caliper/rotor template for the installed wheel
• Supplied as one kit with mounting hardware; spindles, hubs, master cylinder and booster are not included

Fitment & Compatibility

The FDLI package fits the documented GM six-lug rear flange at a 2.46-inch axle offset. Confirm the exact 1971–1991 K-series, Blazer/K5 Blazer, Jimmy or Suburban row and check the installed axle rather than relying on the badge. Its 12.19-inch rotor/hat assembly includes a drum for the supplied mechanical parking shoes.

Use DS1673 to compare the housing bolt layout, 3.55-inch axle register and 6 x 5.5-inch lug pattern. The axle flange must be no larger than 7.05 inches and must have the specified 0.050-inch x 45-degree chamfer. Arrange the hydraulic hoses and parking cable/clevis hardware separately before disassembly.

The table below provides the full application breakdown; match its year, model and brake-configuration details.

Manufacturer Resources

• Exact 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.

PMB Performance brings over 20 years of experience with brake components and fitment details. Send us your VIN together with the installed axle, spindle, brake and wheel specifications if you need help confirming this package.

Vehicle Applications

Application Notes

1. Line kit included (manufacturer): None