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

Wilwood Front FNSL6R GT Package — Red 12.88-Inch Brakes for GM Six-Lug 4x4 (1971–1991)

SKU: 140-18155-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

Red Superlite calipers and 12.88-inch GT-slotted rotors identify this six-lug GM front kit. A conflict between the current GT rotor listing and DS1671 prevents treating either published thickness as settled; confirm the actual rotor pair with Wilwood before purchase. Founded in 1977 by Bill Wood and based in Camarillo, California, Wilwood Engineering designs and manufactures disc brake systems and components for motorsport, street-performance and specialized applications. Its range includes calipers, brake rotors, master cylinders, valves, fittings and brake lines, selected to work together within a properly matched brake system.

Technical Details

  • Manufacturer part number: 140-18155-R
  • Rotor specification: Spec-37 Iron, GT Slotted, vented; 12.88 inches diameter; supplied GT rotor thickness requires manufacturer confirmation
  • Caliper specification: 6-piston Forged Narrow Superlite 6R 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
  • 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

Select this 12.88-inch Superlite conversion by the installed six-lug front hub and the exact GM 4x4 listing. The supported group spans specific 1971–1991 K-series pickups/Suburbans, Blazer/K5 Blazer and Jimmy versions, with no blanket coverage across the entire date range. Verify rotor and caliper clearance using the installation drawing.

DS1671 requires hub stud-hole preparation. Hydraulic planning is also essential: Wilwood specifies a recommended 15/16-inch master cylinder when retaining the factory pedal and vacuum booster, rather than the 1.12-inch OE bore that produces very high pedal effort. Where rear drums remain, follow the recommendation for a 10-pound residual valve plus a proportioning valve in their circuit. Hoses are not supplied.

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.

For fitment help, contact PMB Performance with your VIN and details of any axle, spindle or brake changes. Our team has over 20 years of experience checking parts and fitment, including the dimensions that a model-year search cannot establish.

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 Front Kit 1, 2, 3, 4, 5
1971-1991 GMC Jimmy 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1971-1974 GMC K15/K1500 Pickup 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1971-1974 GMC K15/K1500 Suburban 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1975-1986 Chevrolet K10 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1975-1986 Chevrolet K10 Suburban 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1975-1986 Chevrolet K5 Blazer 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1975-1978 GMC K15 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1975-1978 GMC K15 Suburban 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1979-1986 GMC K1500 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1979 GMC K1500 Suburban 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5
1980-1986 GMC K1500 Suburban 4 x 4 Disc Drum Front Kit 1, 2, 3, 4, 5

Application Notes

  1. Caution: A 15/16” bore master cylinder is recommended for proper brake function when installing this brake kit with the factory brake pedal and vacuum booster.
  2. Wilwood offers a 15/16” bore tandem master cylinder suitable for this application, p/n 260-18184
  3. Using the OE 1.12” bore master cylinder is not recommended and will require very high pedal effort to stop the vehicle.
  4. Line kit included (manufacturer): None
  5. Front line-kit reference: 220-18356