Product Summary

Universal Fit, Rear Position, 11.75 Inch Rotor Diameter

  • Replace those old drum rear brakes with modern disc brakes using this universal weld on disc brake kit
  • Features '69-'77 GM calipers with massive 2.75" piston size to provide incredible stopping power
  • 11.75" OD vented rotors which are .81" thick ensure cool operation for fade free braking performance
  • This complete kit includes calipers, rotors, brake pads, brake hats, caliper slide bolts, and caliper brackets
  • The 1.96" offset CNC machined aluminum brake hat accommodates 5 on 4-1/2, 4-3/4", and 5 on 5" bolt circles

Comes as a Kit

Key Specs

Bolt PatternMulti: 5 on 4.5" | 4.75" | 5"
Rotor Diameter11.75 Inch
Rotor TypeVented
Caliper PistonsOne

Need To Know

This Product Will Ship Free

Shipping Policies & FAQs

Quick and Easy Returns

Return Policy

Speedway Motors 91031935 Details

Replace those old drum brakes with modern rear disc brakes. Mounts .81" x 11-3/4" Pro-lite vented iron rotors and calipers to 3" tube rear end.  Complete with rotors, hats, calipers (7/16"-20 inlets), brackets, brake pads, caliper brackets and slider bolts. 

Wilwood aluminum hats fits 5 lug hubs with 4-1/2", 4-3/4", or 5" bolt circle.



ALL NEW 1969-77 mid and full size GM style caliper is a standard full size GM caliper used for years on many vehicles (1969-72 Chevelle, 73-77 A-Body, 1969-1981 Camaro, 1977 Caprice, S-10 pickups, etc). It will fit any bracket / spindle designed for the large GM calipers (7” mount width). 

  • 7/16"-20 inlet so you can use the readily available brake hoses and hardware from Pre-1978 GM midsize cars
  • IMCA approved
  • Fits 1" thick rotor. 2.8" diameter pistons installed
  • Has 7-1/16" center to center mounting holes
  • The width between mounting tabs is 2-3/4"
  • Depending on the spindle and rotor size it will not fit in most 14” wheels (nor in 15” drum brake wheels)
  • For 1969-1977 GM mid and full-size vehicles
  • IMCA Approved
  • 7/16"-20 Inlet
  • 10mm-1.5 bleeder screw
  • 2.8" diameter pistons

Brake Rotors:

Every rotor is cast from premium grade, long grain carbon iron which exhibits long wear, high thermal stability, and excellent resistance to distortion in high heat. Modern foundry and machining techniques hold close tolerances on face and vane thickness. Combining the correct face thickness with a 32 vane casting provides superior heat management and long service life with low rotating and unsprung weight. The straight vane design also makes it possible to use the same rotor on left or right hand mounting locations.

  • Thickness: GM .810"
  • Outside Diameter: 11.75"
  • # Holes: 8
  • Bolt Circle: 7"
  • Thread: Thru
  • Weight: 8.00 lbs

Brake Hat:

Willwood brake hats have a long standing reputation for fit, performance, and durability. Manufactured from premium grade aluminum alloys offering high strength and low weight.

Rotor Bolt Set:

Ultralight, 5/16-18 thread. Set of 8. With self-locking nuts.

Caliper Bracket:

Mounts 1969-1977 GM mid-size car front caliper to any 3" tube rear end using 11-3/4" diameter rotors. Fully machined steel with punched lightening holes. Measures approximately 7" between mounting holes.

Caliper Slide Bolt:

The overall length of these slide bolts is 4-3/8".  The underhead length is 3-3/8".  The thread on the bolts is 7/16-20 (US fine).

Brake Pads:

Speedway Motors is your one-stop shop for GM 1969-77 A-Body Midsize and 1969-81 F-Body caliper brake pads.

Learn how to properly Bed-In your brake pads by reading our tech article. Bedding-In Brake Pad Procedure.

Aluminum/Steel rotors, best pad for aluminum rotors, low metallic, long life, excellent Street




  • Caliper Brackets (2)
    • Weld onto a 3" axle tube
  • Rotors (2)
    • GM-style .81" x 11-3/4", 8 on 7" bolt pattern
    • Straight vanes, 8 lbs. each
  • Rotor Hats (2)
    • Machined aluminum, 1.96" offset
    • 3.06" center hole, 6-3/8 I.D., 1/2" stud holes, 1.6 lbs.
  • Rotor Bolt and Nut Kit (2)
  • Caliper Slider Bolts (4)
  • Brake Pads (2 sets)
    • Street compound, little metallic, long rotor and pad life
  • Calipers - 1969-77 GM Midsize (L & R)
    • 7/16"-20 inlet
    • Cast iron body, 2.8" single piston

Speedway Motors 91031935 Specifications

MFG. Part #91031935
BrandSpeedway Motors
Bolt PatternMulti: 5 on 4.5" | 4.75" | 5"
Rotor Diameter11.75 Inch
Rotor TypeVented
Caliper PistonsOne
Caliper FinishNatural
Parking Brake ProvisionNo
Rotor ShapeRound
Hardware IncludedYes
Front Rotor IncludedNo
Front Caliper IncludedNo
Rear Caliper IncludedYes
Front Spindles IncludedNo
Master Cylinder IncludedNo
Brake Booster IncludedNo
Rear Rotor IncludedYes
Rotor Hat Bolt Pattern8 x 7.00"
Rotor Thickness.81"
Rotor Backspace1.96"
Thread Pitch7/16"-20
Centerline of Holes7.00"
Sold in QuantityKit
NotesIncludes rotors, rotor hats, caliper brackets, calipers, pads, and hardware.
Rotor Material TypeCast Iron