Product Summary

Universal Fit, Front Position, 5 on 4.75" Bolt Pattern

  • Economical, lightweight brake kit for straight axle hot rods with machined '49-'54 Chevy car spindles
  • Your spindles must be machined or use our reproduction forged spindles
  • Uses 9 1/4" Mustang II rotors (5x4-3/4 bolt pattern) with common GM Metric calipers
  • Includes new rotors drilled with GM bolt pattern, new calipers, bearings, seals, brackets, hardware, and brake hoses
  • Not for '49-'54 cars and will not work with '49-'54 GM truck spindles

Comes as a Kit

Key Specs

Bolt Pattern5 on 4.75"
Rotor Diameter9.25 Inch
Rotor TypeVented
Caliper PistonsOne

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Speedway Motors 91031956 Details

  • Works on all 1949-1954 GM car spindles that have been machined per the included instructions
  • For straight axle hot rod builds only, not for use on 1949-1954 GM car use
  • This kit will not work with stock steering arms, and you must use aftermarket arms
  • Not for use with 1949-1954 GM truck spindles
  • Will work with Speedway Motors forged 1949-1954 GM car spindles with no machining required
  • 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
  • 9-1/4-inch vented rotors are preferred for smaller/lighter hot rods like T-buckets
  • 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 drum brakes on their Model T or Model A, 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 using the popular 1949-1954 GM car spindle for small and light hot rods that do not need "big"disc brakes to stop. These kits provide 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 straight axles that works, is easy to install, and does not require you to mortgage a kidney just to buy it!

Our disc brake kit features Mustang II-style 9-1/4-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 8-1/2 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 56-1/2 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 13-inch wheel; however, we recommend at least a 14-inch wheel with a 2.60-inch hub I.D. that is lug-centric for proper clearance.

The caliper mounting brackets provided fit '49-'54 Chevy car spindles are quite stout to prevent any caliper flex during hard braking. They are direct fit to these spindles but will not work with same year GM truck spindles. Machine work is required to resize the inner and outer bearing surfaces of the spindle pin, shorten the spindle pin, and rethread the retaining nut threads to properly use original spindles with this brake kit. An inner bearing and seal adapter will also be required to be welded in place to properly space the rotor. And if you do not have the means to machine and weld your original spindles for your project, or you do not have any original spindles that is not a problem either, as we offer a beautiful set of forgedGM 1949-1954 car spindlesthat include new king pins with installed bushings that are already modified for our brake kits to help you finish your project. Because the original GM steering arms will not work for a straight axle conversion you will need to update to one of our GM spindlesteering armstoo, 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 Chevy spindle 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 welding (unless you opt for our forged modified reproduction spindles mentioned above) and you will need to replace the inner and outer bearing race in the included disc brake rotor with the new races provided. While there are several methods to install the supplied bearing race, the easiest way is with abearing 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 withthrough-frame fluid line adapters, we have plenty ofbrake hose optionsavailable 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) Rotors

(1) LH Metric Caliper

(1) RH Metric Caliper

(1) Brake Pad Set

(2) Seals

(2) Tapered Inner Wheel Bearing

(2) Outer Wheel Bearing Cup

(2) Wheel Bearing Outer Cone

(2) Caliper Brackets

(1) Bolt Kits

(2) Bearing and Seal Adapter

(1) Spindle Nut Kit

(1) Front Hardware Kit


Speedway Motors 91031956 Specifications

MFG. Part #91031956
BrandSpeedway Motors
Bolt Pattern5 on 4.75"
Rotor Diameter9.25 Inch
Rotor TypeVented
Caliper PistonsOne
Caliper FinishNatural
Parking Brake ProvisionNo
Minimum Recommended Wheel Diameter14 Inch
Rotor ShapeRound
Hardware IncludedYes
Spindle TypeChevy Custom
Rotor StylePlain Face
Front Rotor IncludedYes
Front Rotor Diameter9.25 Inch
Front Caliper IncludedYes
Front Caliper Piston Quantity1
Front Caliper FinishNatural
Rear Caliper IncludedNo
Front Spindles IncludedNo
Master Cylinder IncludedNo
Brake Booster IncludedNo
Brake Hoses IncludedYes
Rear Rotor IncludedNo
Speedway Motors Catalog Part #910-31956
Bore Size2.375"
Bolt Hole Pattern5x4-3/4
Rotor Thickness.88"
Stud Diameter.44"
Stud Length.93"
Thread Pitch7/16"-20
Centerline of Holes5.50"
Sold in QuantityKit
NotesIncludes rotors, bearings and seals, calipers, pads, brake hoses, brake tabs, and caliper brackets
Front Suspension TypeStraight Axle
Rotor Material TypeCast Iron
Brake Hose MaterialRubber