Help is just a click away!
Click here to chat with a Speedway Team Member
Online - Chat with us!
$20 off $299 $40 off $599 $60 off $899 $80 off $1199      Promo: HAPPY    Expires: 7/12/20
$20 off $299 $40 off $599 $60 off $899 $80 off $1199
Promo: HAPPY    Expires: 7/12/20
Products to Compare (max of 3)
Compare These Parts
Talk to the Experts. Call 800.979.0122, 7am-10pm, everyday.
Since 1952
Talk to the Experts. Call 800.979.0122
Shop By
Street Race Truck More... The Toolbox
Add to Cart
Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS
Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS

Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS

Universal Fit, Rear Position, Multi: 5 on 4.5" | 4.75" | 5" Bolt Pattern, Vented Rotor Type

4 Reviews | 7 Answered Questions
In Stock
Ships FREE
Select your vehicle to verify fitment.
Select Vehicle
Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS
Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS
Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS
Basic Weld-On Rear Disc Brake Kit for 1978-88 GM Caliper, 3 In BS
Zoomed In Image
Part # 91031925
Call to Order
Add to Buildlist
What's In The Kit
Videos & Articles
  • Replace those old drum rear brakes with modern disc brakes using this universal weld on disc brake kit
  • Features reinforced weld on brake brackets for use with GM Metric brake calipers
  • 11.75" OD vented rotors which are .81" thick ensure cool operation for fade free braking performance
  • This basic kit includes rotors, brake hats, and caliper brackets to allow you to choose your own calipers
  • The 3" backspace steel brake hat accommodates 5 on 4-1/2, 4-3/4", and 5 on 5" bolt circles

Build Your Kit

You're almost there! This kit has an option or two for you to select. Let us know which options you want for your new kit.
Add to Cart


Bolt Pattern:
Multi: 5 on 4.5" | 4.75" | 5"
Rotor Diameter:
11.75 Inch
Rotor Type:
MFG. Part #:
Rotor Hat Bolt Pattern:
8 x 7.00"
Rotor Thickness:
Rotor Shape:
Thread Pitch:
Hardware Included:
Sold in Quantity:
Includes rotors, rotor hats, caliper brackets, hardware, and instruction sheets.
Rotor Material Type:
Cast Iron


Replace those old drum brakes with modern rear disc brakes. Included steel caliper brackets weld to your 3" tube rearend, making this a universal kit for a variety of applications. Basic kit includes caliper brackets for '78-'88 GM metric car front calipers, Pro-lite vented .810" x 11-3/4" iron rotors, steel brake hats (3" backspace, 6-1/4" I.D.), and rotor bolts.

Hat fits 5 on 4-1/2", 5 on 4-3/4" and 5 on 5" bolt circles.


Brake pad and caliper installation note:  

This bracket features a 90 degree bend in the bracket at the slider bolt threaded area for additional caliper support.  This part of the bracket may or may not interfere with the corner of the inner brake pad backing plate due to differences in brake pad manufacturers.  When this occurs, it will be necessary to simply remove a minimal amount of backing plate material at each corner of the inner brake pad to allow for the necessary clearance between the bracket and brake pad when the caliper and pads are fully installed.


910-31925 Instructions (PDF)

Instructions (PDF)

Important Messages:

  • Get FREE shipping when your order includes this item and exceeds $99! Ground shipping only in the contiguous US.
Some parts are not legal for use in California or other states with similar laws/regulations

Related Products

What's In The Kit

Each kit from Speedway Motors is carefully packaged and delivered right to your door. Below is a list of all the items you should expect to receive when you order this kit. Some of these items may also be available for sale individually if you're here looking for replacement parts.
  • Speedway Pro-Lite Vented Brake Rotor, 11.75 x .81 Inch
    Qty x 2
  • Speedway Stamped Steel Disc Brake Rotor Hat, 3 Inch Offset
    Qty x 2
  • Rotor Hat Bolt Set, 1/8 Inch Thick
    Qty x 2
  • Weld-On 1978-88 GM Metric Caliper Bracket
    Qty x 2
  • Instruct Sheet-Brake Kit
    Qty x 1
  • Speedway 1978-88 GM Metric Brake Pad Spacer
    Qty x 2

More Like This


Q & A

  • Learn how to assemble a rear axle assembly as we put together ours for the 410 Sprint Car Build. Our team of builders continues to make progress on the car!
  • After getting the control arms and drop spindles installed last time, we are dying to see what it looks like on the ground. Today we are working with the Speedway Deluxe Disc Brake Kit. Josh and Joe are on a roll!

You May Also Like