Wilwood rear Forged Narrow Superlite 4R kit components for GM K-Series/Blazer/Jimmy 6-Lug 4x4, red calipers and 12.88-inch gt slotted rotors, with internal parking shoes
Wilwood rear Forged Narrow Superlite 4R assembly for GM K-Series/Blazer/Jimmy 6-Lug 4x4, red caliper and 12.88-inch gt slotted rotor
Wilwood rear Forged Narrow Superlite 4R kit components for GM K-Series/Blazer/Jimmy 6-Lug 4x4, red calipers and 12.88-inch gt slotted rotors, with internal parking shoes
Wilwood rear Forged Narrow Superlite 4R assembly for GM K-Series/Blazer/Jimmy 6-Lug 4x4, red caliper and 12.88-inch gt slotted rotor

Wilwood Rear Red FNSL4R GT Brakes — GM Six-Lug 4x4 (1971–1991), 12.88-Inch Rotors with Mechanical Parking

SKU: 140-18160-R

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Fitment questions?

Call (855) 786-7101 or text (801) 304-3141. We check fitment by VIN.

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Product details

For the listed GM rear axles, this red FNSL4R version combines GT-slotted 12.88-inch rotors with internal drum parking brakes. Its radial-mount service calipers use BP-10 pads and depend on the correct 2.46-inch axle offset. Wilwood Engineering designs and manufactures the disc brake systems and components used throughout its motorsport, street-performance and specialized product range. Bill Wood established Wilwood in 1977, and the company is based in Camarillo, California. Its calipers, brake rotors, valves, master cylinders, brake lines and fittings are selected according to the demands of the whole brake installation.

Technical Details

  • Manufacturer part number: 140-18160-R
  • Rotor specification: Spec-37 Iron, GT Slotted, vented; 12.88 x 1.10 inches
  • Caliper specification: 4-piston Forged Narrow Superlite 4R in Red Powder Coat; radial 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: 17-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

Use this 12.88-inch Superlite rear package on the specified K5 Blazer/K10 housing flange with 2.46-inch axle offset. The table identifies the matching GM six-lug 4x4 models and year splits across 1971–1991, including the related GMC and Suburban applications. Mechanical parking-brake cables must be matched to the supplied internal shoe assemblies.

Before assembly, verify a 3.55-inch axle register and the 6 x 5.5-inch wheel-stud layout. The maximum flange diameter is 7.05 inches, with the drawing’s 0.050-inch x 45-degree edge chamfer. DS1675 explains the rotor/hat alignment and parking-shoe adjustment; cable/clevis parts and hydraulic hoses are not included.

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

Manufacturer Resources

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

Years Make Model Model option Front brakes Rear brakes Kit application Notes
1971-1974, 1987-1991 Chevrolet Blazer 4 x 4 Disc Drum Rear Kit 1
1971-1991 GMC Jimmy 4 x 4 Disc Drum Rear Kit 1
1971-1974 GMC K15/K1500 Pickup 4 x 4 Disc Drum Rear Kit 1
1971-1974 GMC K15/K1500 Suburban 4 x 4 Disc Drum Rear Kit 1
1975-1986 Chevrolet K10 4 x 4 Disc Drum Rear Kit 1
1975-1986 Chevrolet K10 Suburban 4 x 4 Disc Drum Rear Kit 1
1975-1986 Chevrolet K5 Blazer 4 x 4 Disc Drum Rear Kit 1
1975-1978 GMC K15 4 x 4 Disc Drum Rear Kit 1
1975-1978 GMC K15 Suburban 4 x 4 Disc Drum Rear Kit 1
1979-1986 GMC K1500 4 x 4 Disc Drum Rear Kit 1
1979 GMC K1500 Suburban 4 x 4 Disc Drum Rear Kit 1
1980-1986 GMC K1500 Suburban 4 x 4 Disc Drum Rear Kit 1

Application Notes

  1. Line kit included (manufacturer): None