Product Summary

Front Position, 11 Inch Rotor Diameter, Natural

  • Easily installs 11" rotors and '78-up GM "Metric" calipers to your '37-'48 Ford passenger car spindles or '37-'47 Ford pickup spindles for increased stopping power
  • No machine work needed on round back spindle. Minimal modification on square 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
  • Ford 5 x 4-1/2 inch bolt pattern rotor with 2.78-inch hub OD
  • Works with bolt-on steering arms or stock arms

Comes as a Kit

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Key Specs

MFG. Part #91031945
PositionFront
Wheel Bolt Pattern (in.)5x4.5 in.
Wheel Bolt Pattern (mm)5x114.3 mm
Rotor Diameter11 Inch
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Speedway Motors 91031945 Details

  • Works on all 1937-1948 car and 1937-1947 truck spindles
  • Brake kit fits 1937-1941 round back style spindle with zero modifications
  • Also fits 1942-1948 square back style spindles with minor grinding of the spindle
  • This kit works with both cast in and bolt-on steering arms without issue
  • Works perfectly with Speedway Motors spindles which utilize 1937-1941 round back styling
  • Disc brake style wheels are required for proper caliper clearance when upgrading from drum brakes
  • Single 2-3/8-inch piston GM-style "Metric"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 Ford small car 5 on 4-1/2 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 1978-1988 GM "Metric"single piston disc brake caliper. These calipers use a 2.375 (2-3/8-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 D154 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 1937-1941 Ford "round back"spindles. If you have the later 1942-1948 "square back"Ford spindles this kit will still fit with some minor clearance work to the spindle to allow the caliper mounting bracket to properly seat to the spindle. 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. 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!

Kit Includes:

(2) 11 Inch Brake Rotors

(1) Brake Pad Set

(1) LH Metric Caliper

(1) RH Metric Caliper

(1) Disc Brake Kit For 37-48 Ford Spindle

(2) Outer Wheel Bearings

(1) Bolt Kit for Ford Spindle Flat Steering Arms

(1) Spindle Nut Kit

(1) Front Hardware Kit

 

Charts

Speedway Motors 91031945 Specifications

KEY SPECS
MFG. Part #91031945
BrandSpeedway Motors
PositionFront
Wheel Bolt Pattern (in.)5x4.5 in.
Wheel Bolt Pattern (mm)5x114.3 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 4.5"
FinishNatural
ColorNatural
Front Caliper FinishNatural
Front Caliper Piston Quantity1
Application Type37-48 Ford Car Spindle
GENERAL
Sold in QuantityKit
NotesIncludes rotors, bearings and seals, calipers, pads, brake hoses, brake tabs, and caliper brackets.
Bore Size2.375"
Race IncludedYes
Rotor Thickness1"
Stud Diameter0.5"
Stud Length1.5"
Thread Pitch1/2"-20
Centerline of Holes5.5"
Front Suspension TypeStraight Axle
Rotor Material TypeCast Iron
Brake Hose MaterialRubber
Bolt Hole Pattern5x4-1/2

Ratings & Reviews

4.8

133 Reviews

Overall Assessment

This brake kit consistently garners positive reviews with customers often praising the quality, completeness, and ease of installation. The kit's parts are highly regarded for their solid construction and perfect fit, contributing to good performance, especially on hot rod and vintage cars. A few reviews indicate the need for minor modifications during installation or the usage of additional tools, but these issues appear to be infrequent. Overall, customers found it reliable, practical, and an excellent upgrade for their vehicles. The top-notch material quality and functionality of this product have led to numerous recommendations and repeated purchases.

4.8

133 reviews

5

116

4

14

3

2

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1

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0

Most Liked Positive Review

5.0

1948 spindals

this was installed on a 1928 ford Tudor rod, chopped top blah blah blah , fit as described, Grinding necessary on stock square spindle application which was described in the info BEFORE I purchased not after the fact ! the replacement parts are pretty much everywhere and fairly cheap . If you are installing this on the car with spindals already installed on axel then do as they tell you and bake the adapters for 20 minutes and they slide on almost to easy ! make sure after you slide them on with your gloves that you let cool just a little and give them a lite tap with a brass punch to make sure as they cool they didn't back off the spindle just a tad, I did say light tap ! so what are you waiting for ?

Most Liked Negative Review

3.0

I would not buy this product again.

This product is going to be used on my 1929 Model A Ford with a modified original (boxed) chassis and a 4" dropped axle with 4-bar control arms. I am finding it almost impossible to route the brake hoses without encountering an interference with the axle or one of the 4-bar control arms. The Speedway branded calipers are designed to route the brake hoses in a forward direction but the hoses will hit the front axle even when turning slightly to the left or the right in that position. If I cannot find a solution to this issue, I will need to return the product.

Filter by Ratings

Great kit

5.0

24 days ago

Evilruss

Sc

Verified

Heavier duty then what I was expecting. Very nice kit

Would Recommend

Great kit

5.0

24 days ago

Evilruss

Sc

Verified

Heavier duty then what I was expecting. Nice kit

Would Recommend

Your products have always been very good and worked well

5.0

2 months ago

Friend

Oregon

Verified

I have many projects and your tech department has always been very helpful

Would Recommend

Amazing

5.0

4 months ago

james K

Paragould Ar

Verified

Item was well packaged arrived early an was complete with everything in perfect working an usable order

Would Recommend

Yes

5.0

5 months ago

Rob

St. Louis, Mo

Verified

Complete set with all you need. This is second set kit I've installed.

Would Recommend

Simple and effective upgrade

5.0

5 months ago

Ethel

Buffalo, NY

Verified

Used this disc brake conversion to upgrade from the drums on my model T and installation couldn.t be easier. Only trick is getting the spindle adapters hot enough to expand over the factory spindles but with a little coaxing, they seated well. I do recommend coating the calipers with some sort of paint or fluid film as they will rust if not treated.

Would Recommend

Highly recommended

5.0

6 months ago

Blueblood

Ontario Ca

Verified

Quality parts. Only exception was that right and left caliper brackets weren't marked, even though instructions stated so. Had to do a little guesswork

Would Recommend

Yes

5.0

9 months ago

V8

Western Pa

Verified

Front brakes for my Anglia I'm building

Would Recommend

disk brake kit.

5.0

9 months ago

rc

niagara falls ny.

Verified

very easy to install. works great.

Would Recommend

will buy again

5.0

a year ago

allen

mississippi

Verified

easy to install the bolt kit included not so good

Would Recommend

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Showing 10 of 133 reviews

Questions & Answers

57 Questions • 10 Answers

I have new speedway 37-48 Ford spindles. Do I need to remove the stock inner bearing race that comes installed in these rotors and replace it with the new race (912-TL68110) that comes with the kit?

by Luke

• 4 years ago

1 answer

Is this kit compatible with the standard 15 inch "Smoothie" steel wheels clearance wise?

by Cammer8

• 6 years ago

1 answer

hi guys, i have purchased this kit for my hot rod, i now need to purchase wheels.. im stuck between 3.19 and 3.22 centre bore wheels.. which will fit? Regards Pat.

by Pat Boy

• 7 years ago

1 answer

Do I need to change my stock master cylinder to make this work on my 1940 Ford coupe ? If so do you have a bolt on replacement? Thank you

by Tony

• 7 years ago

1 answer

hi reading the reviews your said that with kit # 910-31945 disk brake kit it will add about 4 in a side to the with of the ax. or 8 in overall did i read that right ? looking to add this to my 40 ford front ax that,s on my 30 ford coupe if so that will push my wheels and tiers out about 4in is that right ? thanks john

by john

• 7 years ago

1 answer

I'm looking at brake kit 91031945 which I have used many times and been happy with. My question is whether you could substitute some rotors with a 5 on 5.5" bolt pattern in this kit and if any other parts would need to be purchased to make them work? Thank you.

by Daryl

• 7 years ago

1 answer

Will this kit work on early Ford spindles with cast on steering arms?

by N/a

• 8 years ago

1 answer

kerwinqt@yahoo.com

by Kerwin

• 8 years ago

1 answer

Hi there, could you please tell me the rotor depth measurement from the inside face to the outside wheel flange so I can estimate how much this kit will widen my wheel track from original (drum brakes) Thanks

by Bernie

• 8 years ago

1 answer

i have super bell steering arms will they work with this kit

by burt

• 8 years ago

1 answer

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