Technical 8" Ford brakes

I have a 32 Ford Sedan with an 8" Mustang rear end in it. The brakes are 1.75" wide and I would like to change to 2.25" shoes and drums to provide better stopping. I realize I will probably need offset backing plates and wider drums to accomplish this. Any words of wisdom and parts that I need would be appreciated.

 

What's in front?

 

Dont know if there ever was a wide option on this axle. The offset backing plates from a 9 inch might be made to work by welding holes shut,and redrilling to the small flange pattern.The drum centering hole for the axle may be too large,but some spacer ring might be made to fix that. If you want it bad enough you will figure out how to adapt it.

 

Are the brakes somehow deficient now?

 

Got mid sized Chevy calipers on front with the piston oversized to 2.70 inches with 11” Grenada rotors. Probably just me bit I do not feel as if the car stops as well as I would like. Have not been able to lock the wheels on a panic stop.

 

Remember reading somewhere where a guy used mid '80s Lincoln Town Car 10" x 2-1/2" brakes as an upgrade on either an 8" or 9" small bearing rear. Don't remember the details, tho.

 

Rear brakes are only normally 20-25% of your braking.
What is the diameter of your master cylinder and the pedal ratio?
With no power ***ist 7/8” is recommended.
Your pedal ratio should be 6 to 1. 7 to 1 is even better. 5 to 1 makes for hard braking.
If your 8” rear came from a power brake car, smaller wheel cylinders will also help.

Good luck.

 

Your brakes are plenty big enough both ends. You have issues outside the brakes themselves. A-la along the lines of what @jimmy six is talking about (and maybe other things.)

 

I’m running the same rear brakes on my pickup without issue. Looks like a balance issue either wheel cylinder size or proportioning valve.

 

So far we know nothing about what is operating the brakes: the master cylinder and its specs, the pedal and ratio, boosted or not, what kind of booster if any and so on...

 

If leverage is correct you need a bigger WC or smaller MC for more brake.

 

Stock weight on a 32 Ford sedan was 2310 pounds. Don't know what year Mustang your 8" came from but a '69 'Stang weighed a little over 3000 pounds and a '65 weighed 2606 depending on the engine weight. @jimmy six, @31Apickup, and @X38 have given you some very good information.

 

That was me with the 2.5 inch wide 1980 town car rear finned drums, but I had big register 74 75 maverick shafts, and before I realised that the rear brake drum size of any mid sized Chevy with a 78 up metric caliper was 9.5 inch round by 2 inch wide, so seems like 10 by 3/4 or 2inch wide would suffice and 2.5 be too much, they don't I think make a 2.25 for 10 inch drums, the backplates are shoe width specific. I.e. it's all about where the shoe sits on the upper fulcrum, you think a 2 inch shoe fits 1 3/4 but it's wrong. IF you fit the stock combination valve disc drum into the brakes, and run a booster, the rear brakes I think see 400 ilbs of line pressure or something something so they will never lock up before the fronts. That's the point of it, so, when you jump on the brakes, the back doesn't lock up and you do the spinny spinny

 

Something about an unladen pickup truck with the built in rear line proportioning valve, when laden operates the proportioning valve to give more to the rear perhaps, i.e what do you do in a pickup with a LL the weight to the bow, non over the stern, just do burnouts is the answer

 

Thanks for the answers and suggestions. Looks like I need to dig further to get pedal ratio, mc size and several other specs before I ask any further questions.

 

Here's a start.
https://techtalk.mpbrakes.com/how-to-series/calculating-pedal-ratio

 

I’m running Lincoln 12” brakes up front and have a Fairlane 8” rear with 10” brakes on the 47 Lincoln which weighs probably 3800-4000 lbs and it stops nicely. I’m using the common Speedway hanging pedal, generic Vette master cylinder and dual diaphragm 8” booster. Mine won’t lock up on pavement either, but will in loose gravel. A locked wheel is a wheel out of control.

 

Not sure it'll help, but here's a thread I posted a while back which describes the path I took to address braking problems (caused by multiple issues).

https://www.jalopyjournal.com/forum...e-thread-a-story-with-a-happy-ending.1289583/

 

Hopefully you aren't one of those "2 foot" drivers , riding the brakes can glaze the pads/ shoes & make them less effective . A car that sits a lot can have rust build up on shoes/ pads & reduce their effectiveness . Sometimes simply sanding the friction surfaces will restore a bit of braking efficiency

 

Some Fords in the 60, and 70s had 9" rears with the small backing plate bolt pattern and wheel bearing used on the 8" mustang rear. You can use the 11" backing plates from one of those 9" rears to get 11" by 2" brakes. Drums can be a problem, most drums for the 11" brakes have a bigger hub pilot than the Mustang 8". So you may have to make a spacer for the hub pilot to center the drum and weld it in place.

Also early 90s Explorers used a 10" by 2 1/4' brake. The backing plates will fit the 8" by redrilling the mounting holes in the backing plates. The Explorer drums also have a larger hub pilot than the 8" but a hub pilot spacer can be made for that too.

 

Which always begs the question.
Considering the rear brakes on a 1973 Mustang are now fifty years old. Is there a modern alternative drum brake set up the could be easily fitted to one. Say from a small pickup with a live axle

 

Some pickups had stepped rear wheel cylinders, it may be worth some digging into.

I run GM front discs, 11" x not so wide shoes out back. Speedway Ford-type master and a Summit distribution block wide open. It stops quite well and I have had to really stand on the pedal a couple of times.

 

I used 05 ford explorer, it's almost a bolt on.
Bolt holes need to be elongated to match mount.

 

Roadster Supply has the 11X2.25 rear drum brake kits for the small bearing 8 & 9 inch rear. They do require a 2.50 axle bearing spacing. My 40 coupe has the Maverick rear with 10 inch brakes and Super Bell Power Stoppers in the front and it stops good.