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Disc Brakes with 14-inch Wheels and More Vintage Mustang Tech Questions and Answers
Beyond the Basics
Disc Brakes with 14-inch Wheels
I have a 1965 Mustang hardtop with a 289 and four-speed transmission that I am wanting to do a disc brake swap on. My question is what disc brake kit or setup will allow me to use my “day two” wheels? I currently have a set of 14-inch Keystone Classics on it and would like to continue to run those wheels, as the tires mounted on them now are new. What are the pros and cons to going to a power disc with what I have now? The next question is, if I change the four-speed out for a five-speed for lower highway rpms will a cable clutch and power brakes work together? I will be changing to a dual reservoir master cylinder for safety. I’m just looking for a few ideas to make my Mustang more enjoyable and safe to drive. Thank you.
Staying with the 14-inch diameter wheels will limit your braking effectiveness, even with disc brakes. Most conversion kits for ’65-’66 Mustangs on the market use the original-style 4-piston calipers and rotor to clear the inside of the small wheels. No sense in re-inventing the wheel, so to speak. (Pun intended? —Ed.) Most aftermarket rear disc kits use a late-model T-bird or GM caliper, but again, most kits will not clear the 14-inch wheel. Stainless Steel Brakes sells one with the late-model Ford caliper, part number A111-2 (ssbrakes.com). My biggest recommendation on a disc brake swap kit—stick with a brand name. Some of the mom-and-pop conversions don’t clear or fit as advertised, and they don’t really want to deal with the problem, as they just copied someone else’s kit without knowing any of the engineering behind it. Stainless Steel Brakes makes the front and rear conversion and can be purchased through many of the Mustang vendors or direct from SSBC.
As for the power brake setup, I am currently in the process of converting yet another undersized Chinese brand-X brake booster over to the Mustang Steve booster conversion (mustangsteve.com). The off-brand booster setup was wrong from the start—not enough booster (8-inch dual diaphragm) and the ratio to the pedal was all wrong. The original Ford booster had a bellcrank behind the dash to help with the pedal ratio—so running the booster pushrod direct to the original pedal mount position just doesn’t work. The brakes don’t engage until the pedal is almost to the floor.
Mustang Steve’s kit is engineered using a properly sized 9-inch booster and relocated pedal pin position. The result is brakes that actually work and fit without hitting the shock tower for the dual bowl conversion. I’ve done a half dozen conversions from a bad booster to the Mustang Steve setup and I highly recommend it. And you can buy the whole setup from them or they will sell you the modification plans to do it all yourself.
Regarding the five-speed conversion, the 9-inch booster does get in the way. However, Mustang Steve has a new cable conversion that not only clears the big booster, but also allows the use of a late-model quadrant-style cable setup. The part number for the complete conversion you need is CK165-M, and it is all inclusive. I think the combination of the Mustang Steve’s kit, a set of original-style front disc brakes, and the SSBC rear disc conversion should get you the ride and safety you are looking for.