Mustang II Complete 11 In Front Disc Brake Kit, 5 x 4-3/4 GM BP

#91031943

Mustang II Complete 11 In Front Disc Brake Kit, 5 x 4-3/4 GM BP

Name: Mustang II Complete 11 In Front Disc Brake Kit, 5 x 4-3/4 GM BP
Brand: Speedway Motors
SKU: 91031943
Price: 385.99 USD
Availability: InStock
Rating: 4.8 (42 reviews)

42 Reviews

20 Questions

Easily upgrade your Mustang II based suspension from the stock 9-1/4" rotors to this kit with 11" rotors with powerful GM single piston calipers
No machining required making this a true bolt on upgrade
Fits 1974-1978 Mustang II and 1974-1980 Pinto and Bobcat as well as hot rods with Mustang II suspension

Bolt Pattern:

5x4-3/4"

Caliper Type:

Early Caliper

Metric CaliperWilwood Metric Caliper

Rotor Type:

Standard Rotor

Drilled/Slotted Rotor

$385.99

/kit

In Stock

Quantity

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Product Summary

Front Position, 11 Inch Rotor Diameter, Natural

Easily upgrade your Mustang II based suspension from the stock 9-1/4" rotors to this kit with 11" rotors with powerful GM single piston calipers
No machining required making this a true bolt on upgrade
Fits 1974-1978 Mustang II and 1974-1980 Pinto and Bobcat as well as hot rods with Mustang II suspension
Rotors have 5 on 4 3/4" bolt pattern to allow the use of GM bolt pattern wheels
Detailed instructions are included to simplify installation

Comes as a Kit

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Key Specs

MFG. Part #	91031943
Position	Front
Wheel Bolt Pattern (in.)	5x4.75 in.
Wheel Bolt Pattern (mm)	5x120.65 mm
Rotor Diameter	11 Inch

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Speedway Motors 91031943 Details

Easily upgrade your Mustang II based suspension from the stock 9-1/4" rotors to 11" rotors with powerful single piston GM midsize floating calipers. Kit requires no machining. For use on 1974-1980 Pinto, Bobcat and Mustang II factory spindles.

GM bolt pattern 5 on 4-3/4" (increases track width 1" per side). Includes two 16" front brake hoses and 7/16"-20 banjo bolts with crush washers.

Charts

910-31943 Instructions (PDF)

Guides & Documents

Disc Brake Kits Installation Instructions (91031943)

Disc Brake Pads Technical Information (9193382)

Brake Pad Identification and Friction Surface Options Explained

Speedway Motors 91031943 Specifications

KEY SPECS
MFG. Part #	91031943
Brand	Speedway Motors
Position	Front
Wheel Bolt Pattern (in.)	5x4.75 in.
Wheel Bolt Pattern (mm)	5x120.65 mm
Rotor Diameter	11 Inch
Rotor Type	Vented
Caliper Pistons	One
Caliper Finish	Natural
Parking Brake Provision	No
Minimum Recommended Wheel Diameter	15 Inch
Rotor Shape	Round
Hardware Included	Yes
Rotor Style	Plain Face
Front Rotor Included	Yes
Front Rotor Diameter	11 Inch
Front Caliper Included	Yes
Rear Caliper Included	No
Front Spindles Included	No
Master Cylinder Included	No
Brake Booster Included	No
Brake Hoses Included	Yes
Rear Rotor Included	No
Bolt Pattern	5 on 4.75"
Finish	Natural
Color	Natural
Front Caliper Finish	Natural
Front Caliper Piston Quantity	1

GENERAL
Sold in Quantity	Kit
Notes	Includes rotors, bearings and seals, calipers, pads, brake hoses, brake tabs, and caliper brackets.
Rotor Thickness	1.05"
Stud Diameter	0.44"
Stud Length	0.8"
Thread Pitch	7/16"-20
Centerline of Holes	7"
Rotor Material Type	Cast Iron

Ratings & Reviews

4.8

42 Reviews

Overall Assessment

Overall, customers commend the product for its impressive quality, functionality, and affordability. A common theme among the reviews is the ease of installation, thanks to the straightforward instructions and comprehensive kit. The product's compatibility with a range of vehicles, from classic cars to trucks, was praised. Users also reported a significant improvement in braking power after installation. However, a few noted the hub grease seal is quite tight, requiring careful installation, and the lug studs' length was a concern for some. Despite these minor issues, customers are generally satisfied and highly recommend the kit for brake upgrades.

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4.8

42 reviews

Most Liked Positive Review

5.0

outstanding brake set up , fit great

this is a great complete kit, was really easy to install and comes with good instructions. everything in the kit looked like quality heavy duty stuff! was very happy with it.

Most Liked Negative Review

3.0

Adequate.

Parts arrived quickly and were in decent quality. Instructions were straight forward. Swapped in place of my OEM Mustang 2 parts. Unfortunately this kit with GM rotors pushes the track width out and inch on either side (+2" track change over all). I had do dig deep into the questions to find that info. I'm not upset, just disappointed in myself for not researching and with speedway for not openly disclosing that info. Insult to injury, the lug studs are kinda short and and really only go half way into my lug nuts with steel wheels.

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I would recommend this product and buy it again

5.0

5 months ago

Car Guy

Alberta Canada

Verified

Installed it on a 35 Ford Slantback. It has a Mustang II cross member, the brakes were only 9 inch, the 11 inch is a big upgrade, stops way better. Kit was easy to install, required one shim on each side to properly align the lower calliper bracket

Would Recommend

Quality parts

5.0

2 years ago

Normy

Scobey,MT

Verified

Instructions would be a benefit but was easily figured out

Would Recommend

Quality products

4.0

2 years ago

Jakester821

Smithtown Long Island NewYork

Verified

I used this brake package to up grade my 39 Chevy with Mustang II suspension. It was easy to install and improved the braking. The only fault I can say is that the wheel studs are too short. I have plain steel wheels and the lug nuts only threaded on about 3/4 of the way. If you have a thicker mag style wheel, you may have problems.

Would Recommend

Work great on my 46 Ford.

5.0

2 years ago

Russ

Maine

Verified

Installed these on my 46 Ford truck. Work excellent. Using in 4 wheel disc setup. Strong braking power overall. Very straight forward install.

Would Recommend

Iwould buy this again

5.0

2 years ago

jarhead

Evansville In.

Verified

INSTALLED ON MY WIFES 48 CHEVY STEPSIDE. VERY EASY INSTALLATION. WOULD RECOMMEND TO OTHERS.

Would Recommend

Iwould buy this again

5.0

2 years ago

jarhead

Evansville In.

Installed on my 57 chevy with little effort, I cant think of any changes I would make.

Would Recommend

Yes

5.0

2 years ago

Turtle

Calgary Alberta CA

Verified

Building hot rod

Would Recommend

great value

5.0

3 years ago

joe

simi valley ca

Verified

used this brake upgrade kit on my 1941 chevy truck that has mustang 2 front suspension

Would Recommend

Fit like We hoped. Brake kit contained everything

5.0

3 years ago

Shelby

Missouri

Verified

Replaced front brakes and wanted to replace everything. For a single piston this worked well.

Would Recommend

Good quality

5.0

3 years ago

Mike

Modesto Ca

Verified

Just make sure to read the instructions. You must remove stock races installed in the rotors and install the races provided in the kit

Would Recommend

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Questions & Answers

20 Questions • 10 Answers

Sort Questions

How do i identify what year Mustang II front end i have that was installed on a 1935 ford truck foor it 's front end which i just purchased

by Eric

• 8 years ago

1 answer

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Will this Speedway Disc brake kit part #91031943 work with 2" dropped spindles?

by Dennis

• 8 years ago

1 answer

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Hello will this kit fit a 1969 Mustang

by Jordan468

• 9 years ago

1 answer

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Will this work with the master cylinder for stock Mustang 2 disk brakes?

by Jim

• 9 years ago

1 answer

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I bought this kit and finally got around to installing it. I have run into a problem with the calipers retracting the piston too far, however. Every pump of the brake pedal pushes out the piston, and when the pedal is let up, the piston retracts all the way back in. I have researched this problem, and it seems if the calipers are the GM "Low Drag" type, they require a stepped, or 2 stage master cylinder. Is it possible that I received calipers of the "low drag" variety? Then they won't work with my standard master cylinder. Do you have a recommendation for a caliper that will fit this kit that is the standard, NOT low drag variety?

by DarthBulk

• 9 years ago

1 answer

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I have fitted this kit to my 54 chevy truck and used your 2" dropped spindles ( as the caliper brackets on my original mustang II wouldnt fit my old spindles when I was on the old 9.5" rotors ). I have now fitted one of your speedway crossmembers and I now need "normal" standard spindles, as the clip has dropped me real low at the front!! What spindles do I need please

by Dave

• 9 years ago

1 answer

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I have a 1950 Ford F1 that already had a Mustang II conversion done. I'm planning on upgrading to a 68-72 F100 9" rear end which has a 5x5.5 bolt pattern. Is there a kit which would include rotors with this bolt pattern? Thanks.

by Flathead Jim

• 9 years ago

1 answer

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what is the difference between part# 910-31950 and part # 910-31943? They are both for 74 and up mustang, bobcat, pinto spindles. And the parts list appear the same.

by 52coupe

• 10 years ago

1 answer

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will this work on a 76 Camaro?

by kosmoscw

• 10 years ago

1 answer

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are the bearings made to fit the rotors or mustang spindel

by jim

• 10 years ago

1 answer

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Fitment

1974-1980 Ford Pinto

1975-1980 Mercury Bobcat