Menu

Shop

Garage

Cart

Account

Product Summary

Front Position, 11 Inch Rotor Diameter, Natural

  • Upgrade your Mustang II from the stock 9 1/4" rotors to 11" rotors with powerful single piston floating caliper
  • Simple bolt-on conversion includes instructions & requires NO machining
  • For use on '74-'80 Pinto or Bobcat and '74-'78 Mustang II spindles
  • Complete kit includes new rotors, calipers, rubber brake hoses, brackets, bearings, seals, pads and hardware
  • Features Ford 5 x 4 1/2" bolt pattern with 1/2" wheel studs

Comes as a Kit

See more details

Key Specs

MFG. Part #91031944
PositionFront
Rotor Diameter11 Inch
Rotor TypeVented
Caliper PistonsOne
See more specs

Need To Know

Quick and Easy Returns

Return Policy

Speedway Motors 91031944 Details

Calipers-

  • Uses common 7/16-20 SAE thread fluid inlet for larger brake hose compatibility
  • Caliper features low-drag piston seal and piston dust seal for long life/street use
  • Available as left or right side casting, only buy what you need for service/repairs
  • Uses commonly found FMSI D154 reference number disc brake pads
  • No core charge required and no need to ship your old calipers back
  • Designed for 1.00-inch thick disc brake rotors (can fit .810-inch rotor with pad spacer)
  • Uses 5-1/2-inch bolt spacing mounting pattern
  • Brake pads, brake hoses, and caliper slide bolts sold separately

Stop Effectively with Our IMCA Approved GM Metric Disc Brake Calipers

Spec class racing removes a lot of the “wallet racing” by equalizing the racing equipment and focusing on the racer’s abilities. Having rules that specify specific parts, weights, dimensions, and more means everyone, theoretically, is running the same car with the same performance, making the race more about driver skill and race strategy. It is a great, cost effective, way to go racing while being competitive and having some fun.

One such spec item the IMCA mandates for many of their racing classes, including Modifieds, Hobby Stock, and others, is the use of the ’78-’88 GM Metric caliper. Having the same caliper body and piston size as an approved IMCA part means everyone has the same braking system capability. The issue has been finding a good GM Metric caliper though. Parts store remans are iffy at best, often being remanufactured with substandard parts, and requiring core charges or turning in your old calipers. We opted to craft a brand new reproduction steel brake caliper that meets all the class rules for IMCA approval but can also be used on the street with any aftermarket brake system that specs these GM Metric calipers for their brake kit.

Brand New Casting with Low Drag Piston Seal and Street Friendly Dust Seals

When we designed our IMCA approved GM Metric disc brake caliper we realized the majority of the sales would come from racers, but we also wanted to ensure that this disc brake caliper could be used in road going applications, as this brake caliper is very popular in rear disc brake conversions and for custom installations using caliper mounting brackets, either application specific or universal clamp-on or weld on options.

To that end, we fitted the 2-3/8-inch diameter piston with a low drag piston seal that retracts the piston slightly, pulling the brake pads away from the rotor for better fuel economy. Furthermore, standard piston dust seals are included in our brake caliper casting for extremely low maintenance requirements. These disc brake pistons are designed to fit best with 1-inch wide disc brake rotors but will work with .810-inch rotors as well when fitted with our disc brake pad spacer.

When designing these new Metric calipers, we did change the fluid port to the much more common 7/16-20 thread. This opens up your brake hose and banjo bolt/fitting options immensely for custom applications. Our 16-inch braided Teflon brake hose kit is a great option that will work for most applications, but we offer several different brake hose kits in various lengths for your project needs. We do not include brake caliper slide bolts and highly recommend our one-piece caliper slide bolt (two per caliper) that does not use the factory slide bolt bushings in the caliper. These GM Metric calipers use readily available replacement or performance disc brake pads found under the FMSI D154 pad shape reference number.

Upgrade your Mustang II based suspension from the stock 9-1/4" rotors to our 11" rotors with powerful single piston GM metric floating calipers. This simple bolt-on conversion requires no machining. For use on 1974-80 Pinto, Bobcat and Mustang II spindles.

Features a 5 on 4-1/2" Ford/Mopar wheel bolt pattern (increases track width 1/2" per side). Includes two 16" front brake hoses and 7/16"-20 banjo bolts with crush washers.

Note:  14" wheels will require clearance to be checked as not all 14" wheels will clear caliper

Brake Pads-

Speedway soft brake pad for GM Metric 1978-Up.

  • Powder-coated backing plates help prevent corrosion
  • Multi-layered OE style shim provides quieter braking(where applicable)
  • Friction material matched to your vehicle's OE standards
  • Provides reliable performance
  • Sold as one set of 4 (ST); outfits two calipers.

 

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

Bearings & Seals-

Works with Mustang II/Pinto and Granada rotors using Mustang II/Pinto spindles only. It will not work for installing Mustang II/Pinto brake rotors on 1949-1954 Chevy spindles. Not for use with early Chevy spindle brake conversion kits.

-Large Bearing-
Thickness: .656"
Upper OD: 1.900"
Lower OD: 2.150"
Bearing ID: 1.375"

-Small Bearing-
Thickness: .651"
Upper OD: 1.380"
Lower OD: 1.570"
Bearing ID: 0.864"

For Mustang II/Pinto and Granada rotors using Mustang II spindles.

IMCA Approved.

Charts

Speedway Motors 91031944 Specifications

KEY SPECS
MFG. Part #91031944
BrandSpeedway Motors
PositionFront
Rotor Diameter11 Inch
Rotor TypeVented
Caliper PistonsOne
Caliper FinishNatural
ColorNatural
Parking Brake ProvisionNo
Rotor ShapeRound
Hardware IncludedYes
Rotor StylePlain Face
Front Rotor IncludedYes
Front Rotor Diameter11 Inch
Front Caliper IncludedYes
Rear Caliper IncludedNo
Front Spindles IncludedNo
Master Cylinder IncludedNo
Brake Booster IncludedNo
Rear Rotor IncludedNo
Bolt Pattern5 on 4.5"
Front Caliper FinishNatural
Front Caliper Piston Quantity1
GENERAL
Sold in QuantityKit
NotesIncludes rotors, bearings and seals, calipers, pads, brake hoses, brake tabs, and caliper brackets.
Rotor Thickness0.88"
Stud Diameter0.5"
Stud Length1.29"
Thread Pitch1/2"-20
Centerline of Holes5.5"
FinishNatural
Rotor Material TypeCast Iron

Ratings & Reviews

4.9

80 Reviews

Overall Assessment

Customers consistently praise the product for its quality, practicality, and ease of installation. The product showcases excellent material quality and usability, with many noting that it fits perfectly and improves performance. The detailed instructions are appreciated by clients, both experienced and novices. The safety feature stands out, as users report a significant improvement in brakes. A common recommendation is to consider a lightweight alternative, but overall, our product is deemed superior, with excellent practicality and value. Customers find it's a worthwhile upgrade despite extra costs compared to other brands.

4.9

80 reviews

5

70

4

10

3

0

2

0

1

0

Filter by Ratings

Yes

5.0

2 months ago

Grampot

BOTHELL WA

Verified

Ordered to complete a new IFS in a 1954 Chevy 210. Parts arrived as ordered and fit well

Would Recommend

I would definitely recommend this .

5.0

2 months ago

68joe

San Diego, California

Verified

This was an easy install and looks great on my project.

Would Recommend

Good Quality Brake Kit

4.0

3 months ago

JJR

Lynn, MA

Verified

Just inventoried components. Will not assemble till Spring. Good quality stuff

Would Recommend

Great product,

5.0

9 months ago

Mustang ii cobra guy

Illinois

Verified

Product is really good and awesome. Easy install on my Mustang ll, 14x7 I

Would Recommend

Fits perfect.

5.0

a year ago

J

Montana

Verified

I would buy again if I needed to it last longer than me. Fits tge qa1 mustang 2 front suspension kits.

Would Recommend

best option for custom projects

5.0

a year ago

sandy

florida

Verified

I used this to build an IFS onto a 69 mustang coyote swap. best affordable option with higher than price quality.

Would Recommend

Great upgrade

4.0

a year ago

Russ

Paducah, Ky.

Verified

Parts fit great, good quality, everything you need are included, good value.

Would Recommend

Yes I would buy again

5.0

a year ago

Tim

Texas

Verified

Replaced mustang ll 4 lug rotors and all control arms. Everything fit perfect. Very pleased.

Would Recommend

Yes

5.0

a year ago

Jb

Baker city oregon

Verified

It's a complete break, set up for Ford Mustang two

Would Recommend

BEST HOT ROD PRODUCTS

5.0

a year ago

37 HOTRODER

PARKER CO

Verified

kit was very easy too install have GOOD BRAKES NOW!!!!

Would Recommend

Load More Reviews

Showing 10 of 80 reviews

Fitment

      Customer Impersonation Script