Product Summary

Front Position, 11 Inch Rotor Diameter, Natural

  • Easily installs 11" rotors and 1969-1977 GM "Midsize" calipers to your '37-'48 Ford passenger car spindles or '37-'47 Ford pickup spindles for increased stopping power
  • No machine work needed on square back spindle. Minimal modification on round back spindles
  • Includes new rotors and semi-metallic pads, new bearings and seals, new caliper bolts and calipers, along with caliper mounting brackets, bushings, hardware, and hoses
  • GM 5 x 4-3/4 inch bolt pattern rotor with 2.78-inch hub OD
  • Works with bolt-on steering arms or stock arms

Comes as a Kit

See more details

Key Specs

MFG. Part #91031942
PositionFront
Wheel Bolt Pattern (in.)5x4.75 in.
Wheel Bolt Pattern (mm)5x120.65 mm
Rotor Diameter11 Inch
See more specs

Need To Know

Quick and Easy Returns

Return Policy

Speedway Motors 91031942 Details

  • Works on all 1937-1948 car and 1937-1947 truck spindles
  • Brake kit fits 1942-1948 square back style spindles with zero modifications
  • Also fits 1937-1941 round back style spindle with minor grinding of the spindle
  • This kit works with both cast in and bolt-on steering arms without issue
  • Will work with Speedway Motors spindles if clearance is provided
  • Disc brake style wheels are required for proper caliper clearance when upgrading from drum brakes
  • Single 2-13/16-inch piston GM-style "Midsize"calipers use commonly available replacement pads
  • Street friendly organic brake pad compound for long pad and rotor life
  • Performance brake pad upgrades available separately for those wanting increased stopping power
  • Includes everything you need to convert from drum to disc brakes with all new parts
  • 11-inch vented rotors create superior stopping power to drums, especially for heavier cars
  • Rotors feature standard GM 5 on 4-3/4 wheel stud bolt pattern

Add Disc Brakes to Your Straight Axle Hot Rod with Bolt-On Ease

We understand that the traditional straight axle hot rodder is going to want to keep the look of early Ford brakes and their finned drums on their Model A or 32 roadster if at all possible. However, we know there is a large base of builders that want their classic looks but with modern handling, braking, and comfort. Face it, if your hot rod is a miserable ride that will not stop you are not going to want to drive it. We get it. For those enthusiasts, a small amount of leeway in their hot rod's traditional looks is acceptable to make it a fun long-distance cruiser that can be safely operated in today's traffic. One of the top safety upgrades we see is updating these straight axle hot rods with front disc brake kits. Speedway Motors offers several complete disc brake conversion kit options with everything you need to get the job done on your spindles, and if you do not have spindles for your hot rod straight axle setup, well, we have those as well!

Everything You Need and Everything New

Time is our most precious commodity and something that we cannot ever obtain more of. So why waste your valuable time scouring parts stores, junkyards, and Internet forums for DIY "piece it together"disc brake conversion solutions that will only cause you frustration in the garage and lead to further delays and parts searching? Speedway Motors, a leader in street rod parts, understands how important your time is, which is why we have done all the time sensitive research and parts sourcing to build the most complete Model A brake upgrade with our straight axle drum to disc brake conversion kit package for early Ford spindles that works, is easy to install, and does not require you to mortgage a kidney just to buy it!

Our disc brake kit features 11-inch vented rotors that are paired with the popular 1969-1977 GM "Midsize"single piston disc brake caliper. These calipers use a 2.8125 (2-13/16-inch) diameter piston and offer excellent stopping power in a floating caliper design. We include standard organic brake pads, but the caliper can be upgraded with any D52 performance pad of your liking should you desire a bit more pad "bite"in your system. Also included in our kit are new brake fluid hoses, bearings, seals, dust caps, and all mounting hardware. This brake kit will add 8-1/4 inches overall to your straight axle's center-to-center distance of your king pins. Meaning, if you are running a 48-inch axle, your overall width once installed will be 56-1/4 inches. This may be more or less than your current setup depending upon current brake package and wheel spacers. This kit requires a minimum of a 14-inch "disc brake" wheel, however we recommend a 15-inch wheel with a 2.80-inch hub I.D. that is lug-centric for proper clearance.

The caliper mounting brackets provided fit '37-'48 Ford spindles and are quite stout to prevent any caliper flex during hard braking. They are direct fit to the 1942-1948 "square back"Ford spindles. If you have the earlier 1937-1941 Ford "round back"spindles this kit will still fit with some minor clearance work to the spindle to allow the caliper to properly seat to the caliper mounting bracket and not bind up. And if you do not have any spindles at all for your project that is not a problem either, as we offer a beautiful set of forged Ford round back spindles that include new king pins with installed bushings to help you finish your project (they will need the same minor modification just like original spindles). Do not forget your steering arms too, especially if you are using a drop axle, as aftermarket steering arms will save a lot of time and frustration in this regard.

An Easy DIY Installation You Can Complete in Your Home Garage

We have included everything you will need in our Ford straight axle disc brakes conversion kit, right down to the spindle nut with retainer and cotter pin, new bearings, brake hydraulic hoses, and more. With such a complete kit you will have your hot rod's front brakes upgraded and back on the road in no time. The included inner bearing adapter that fits over the spindle requires a small press for installation (or you can heat it up to allow expansion and slip it on that way) and you will need to replace the inner bearing race in the included disc brake rotor with the new race provided. While there are several methods to install the supplied bearing race, the easiest way is with a bearing race and seal driver. It is a very handy tool for removing and installing bearing races and bearing seals. Everything else in the kit will install with traditional hand tools any hot rodder will surely have in their toolbox.

The included brake hoses feature a 7/16-20 thread banjo bolt with sealing washers for the caliper end and standard 3/8-24 inverted female flare for the frame end and your 3/16-inch brake hard line. These brake hoses are 18 inches in length and should work for most applications. However, if you need a different length brake hose to clear four-link style front ends or prefer an AN hose with through-frame fluid line adapters, we have plenty of brake hose options available to suit your specific build style and clearance requirements. Adding disc brakes to your pre-war straight axle hot rod has never been easier thanks to Speedway Motors and the value you get for your money means more budget left over for those T-bucket parts you need!

Charts

Specs

This kit widens track width .75" per side

Speedway Motors 91031942 Specifications

KEY SPECS
MFG. Part #91031942
BrandSpeedway Motors
PositionFront
Wheel Bolt Pattern (in.)5x4.75 in.
Wheel Bolt Pattern (mm)5x120.65 mm
Rotor Diameter11 Inch
Rotor TypeVented
Caliper PistonsOne
Caliper FinishNatural
Parking Brake ProvisionNo
Minimum Recommended Wheel Diameter15 Inch
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
Brake Hoses IncludedYes
Rear Rotor IncludedNo
Bolt Pattern5 on 4.75"
FinishNatural
ColorNatural
Front Caliper FinishNatural
Front Caliper Piston Quantity1
Application Type37-48 Ford Car Spindle
GENERAL
Sold in QuantityKit
NotesRequired diameter for wheel clearance is 12.6". Spindle centerline to outboard caliper side is 6.3".
Bore Size2.8125"
Rotor Thickness1.05"
Stud Diameter0.44"
Stud Length0.8"
Thread Pitch7/16"-20
Centerline of Holes7"
Front Suspension TypeStraight Axle
Rotor Material TypeCast Iron
Brake Hose MaterialRubber
Bolt Hole Pattern5x4-3/4

Ratings & Reviews

4.8

36 Reviews

Overall Assessment

Customers are consistently satisfied with this brake kit, stating it works great on various projects, especially older Ford models. Users commend its ease of installation and the quality of its components. The kit is known for its perfect fit, practicality, and performance enhancement. Moreover, customers express appreciation for the inclusion of multiple part numbers, which despite sometimes leading to excess pieces, ensures a comprehensive package. This product is repeatedly bought by customers and highly recommended for its reliability and value. It's considered an upgrade on competitor products, with superior usability and finish, further solidifying its position in the market. Notably, the kit's compatibility with commonly available parts is a plus for ease of replacement.

4.8

36 reviews

5

30

4

6

3

0

2

0

1

0

Filter by Ratings

Yes

4.0

9 months ago

Ted

Michigan

Verified

Work in progress, brakes are for my 32 Ford project.

Would Recommend

Yes without reservations

5.0

2 years ago

Jim

Bakersfield Ca

Verified

It worked out great on 1929 model A pickup Steve in technology helped outstanding

Would Recommend

good part for frame build to complete front end

5.0

4 years ago

Stephen

massachusetts

Verified

to complete front build for model project

Would Recommend

I would buy this again

5.0

5 years ago

N/A

Idaho Falls Idaho

Verified

Very nice kit

Would Recommend

i did buy this product again!

5.0

5 years ago

Smacksy

Charles City ia.

Verified

I have used these on several projects. Work great !

Would Recommend

Money well spent!

5.0

5 years ago

Bennieboy

Dacusville SC

Used this kit in conjunction with a Speedway Motors 1" bore Master cylinder on a 1946 Ford Pickup Rat Rod. Works like a champ! I am very happy with the products provided and even more pleased with the performance. You will not be disappointed when you install this on your older Ford.

Would Recommend

Speedway never disappoints. Great products and fast shippi.

5.0

6 years ago

Blue Collar Hot Rods

Franklin TN

Verified

Used this brake kit on a '23 T Roadster. I've used these several times, and works great.

Would Recommend

Perfect in every way

5.0

7 years ago

Low low

Spooner WI

Verified

Used on my rat rod would always buy from Speedway Motors

Would Recommend

Another great kit. Read instructions first.

5.0

7 years ago

Slim

NY

Verified

Nice fit and finish.

Would Recommend

I have used these before with great success and will again.

5.0

7 years ago

old f t

missouri

Verified

Work just as designed and are very user friendly.

Would Recommend

Load More Reviews

Showing 10 of 36 reviews

Questions & Answers

22 Questions • 11 Answers

Hi, is it possible to upgrade this kit with another calipers or pads? I ve got this one on my 29 and find its not really efficient ( the technique inspection give not really good values). I précise that the mastercylinder is à brand New wilwood with aviation brake hose and the good pedal ratio and there s no air in the circuit

by Clément

• 3 years ago

1 answer

Do you have a drilled and slotted rotor that will fit this kit .

by Rick

• 7 years ago

1 answer

will this kit work with stock 47 ford pickup spindles

by rusty

• 7 years ago

1 answer

Why do you not have this in 5 on 5.5 bolt pattern.? Can I get it blank so I can make 5 on 5.5 ?

by Bill

• 7 years ago

1 answer

Hallo, I ask you if is possible to mount the part # 91031942 (Disk Brake Kit) on the SOCALOOK® VW Beetle Straight Tube Axle Front End Kit Thank you Massimo

by Massimo

• 8 years ago

2 answers

What would the hub face width be with a 48 inch king pin Axle such as #7021021D? Vehicle is a 1931 Model A coupe with modified fenders. Thank you for your response!

by Ms Wred

• 9 years ago

1 answer

What kind of master cylinder would you recommend for these brakes?

by Aidan

• 9 years ago

1 answer

I want to buy this kit for my father in law and he has a 1936 Ford Pickup. Will this kit bolt up to his all original front axle and spindles?

by Ryan

• 9 years ago

1 answer

Maybe I missed it. Will this kit work with a 14x6 wheel w/ 3.74 back spacing? I think I saw someone mention it was 12.75 diameter overall. Thank you.

by Rob

• 9 years ago

1 answer

Will I be able to use my 1937 Ford wide five wheels with the wide five 4 3/4 adapter plate on this disc kit ?

by Zeke

• 10 years ago

1 answer

Load More Questions

10 of 22 questions shown

Fitment

          Customer Impersonation Script