Product Summary

64-66 Ford Mustang, Disc/Disc Brake System Type

  • 7" Single black Mustang booster w/ firewall plate
  • 1" Bore master cylinder, 1/2-20" & 3/8-24" ports on left side only
  • Includes pre-bent lines to master cylinder
  • Built in residual valve for rear brakes
  • Mounting hardware included
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Key Specs

MFG. Part #91664048
BrandSpeedway Motors
Brake System TypeDisc/Disc
Brake Booster Diameter7 Inch
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Need To Know

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Speedway Motors 91664048 Details

This is one of our best selling power brake units for your early Mustang. Want to add power brakes but fear it will hit the shock towers? Not this unit! Sure to slip right in and clear under the hood and get the stopping power you deserve. Retain the OEM look and add power brakes to your Mustang today!

1964-1966 Ford Mustang Booster Conversion Kit (Disc/ Disc)

Conversion Kit Includes

  • 7" Single Black Mustang Booster w/ Firewall Plate
  • 1" Bore Master Cylinder
  • 2227161 Casting Number with Teardrop Markings
  • 1/2-20" & 3/8-24" Ports on left Side only
  • Bottom Mount Universal Disc/Disc Proportioning Valve Kit
  • Includes Pre-bent Lines to Master Cylinder
  • Built in Residual Valve for Rear Brakes
  • Zinc Bottom Mount Bracket
  • Mounting Hardware

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Speedway Motors 91664048 Specifications

KEY SPECS
MFG. Part #91664048
BrandSpeedway Motors
Brake System TypeDisc/Disc
Brake Booster Diameter7 Inch
GENERAL
Brake Booster TypeVacuum Diaphragm Single
Outlet CountTandem
Outlet Fitting1/2"-20 & 3/8"-24
Master Cylinder Bore Size1 Inch
Master Cylinder Port Sizes3/8"-24 & 1/2"-20 IFF
Master Cylinder Built-In Residual ValvesYes
Master Cylinder Bail TypeSingle Bail
Mounting Bracket IncludedYes
Proportioning Valve IncludedYes
Proportioning Valve LocationBottom Mount
Reservoir IncludedYes
Sold in QuantityKit

Ratings & Reviews

4

3 Reviews

Overall Assessment

Customers appreciate the product's easy installation, especially notable since some aren't professional mechanics but hobbyists. It fits well in a Mustang of old vintage, and even comes with adjustable features like the booster pushrod, though some adjustments may be necessary for optimal performance. Quality of materials is demonstrated through the product's reuse of existing holes and replaceable brake lines. While it may initially be a bit time-consuming and complex, ultimate engagement is assured with the appropriate tools. Customers recommend the product for its practicality and usability.

4

3 reviews

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Upgraded 65 mustang to Disc-Disc

5.0

5 years ago

Rob

West Michigan

Verified

This was an easy installation for my 65 Mustang. I replaced my 56 year old brake lines so I cannot comment on what it would take to reuse the existing. The existing holes were reused. I did need to get new bolts for the fire wall adapter since I was replacing a 2 bolt factory unit, simple drive to NAPA. - Oh - I am not a mechanic, just a hobbyist.

Would Recommend

ez install

5.0

6 years ago

db

ft collins

Verified

ez install take your time to insure good fit on your lines

Would Recommend

Be sure to check booster pushrod length

2.0

6 years ago

Don

Texas

The booster pushrod is adjustable but even in max out condition and using extension shipped with booster, was too short to get proper MC engagement. Had to remove their extension screw and fabricate a longer one from a metric SS screw to get proper engagement. Do yourself a favor and purchase the depth checking tool to ensure proper engagement. On a 66, this is tight and a PITA to R&R.

Would Not Recommend

Showing 3 of 3 reviews

Questions & Answers

2 Questions • 2 Answers

Will this work with a manual transmission?

by Corey

• 3 years ago

1 answer

What pedal would you recommend for this. I'm installing in a 52 f-100 . Kit looks complete , is there anything else that is needed for instalation? does this use vacuum from the intake.

by None

• 5 years ago

1 answer

2 of 2 questions shown

Fitment

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