I am planning to upgrade to manual disc brakes in an E body small block Cuda (the car only has about 11" of vacuum at idle) from manual drum brakes. I'm wanting to know if it will stop well enough, ie anyone has found a manual disc set up to be less than sufficient? Thanks

I recently swapped from manual drums to manual disc and a 15/16" master cylinder on my 340 Challenger. The car stops with no problems at all!

I've had Wilwood manual discs on two different cars and they both stopped awesome.

The 69 Dart has manual disc that work great. I robbed everything from a 74 Dart 4 door car.
I made sure to save the original brake proportioning block and used a 15/16" Aluminum Master Cylinder and 4-2 bolt adapter from Dr. Diff. No regrets...

I've got 4-wheel manual disks on my '71 Charger and have never missed having a power booster.

I have a big block in my 70 Cuda and run a KOS class at the local track. It has discs on the front from a Chrysler Cordoba and stock rear drums. They are manual.

The car stops fine from over 100MPH even when hot lapping.

The manual disc with the 15/16" master cylinder isn't bad on the Cuda. It doesn't feel like new car power brakes, but its fine for normal driving. Maybe its only my imagination, but I felt the pedal effort was reduced when upgrading the rotors from the factory size to the 11.75.

I had manual front discs on mine before I tore it down, it was ok for the street. Given I will be road coursing my car, I'm heavily considering going to hydro-boost..

Talk about no feel

And that's the major downside of the idea.

My understanding, the details make a lot of difference to get a workable setup. Smaller bore master, plenty of brake piston area, and higher friction pads. The low cost organic pads bite well cold... but do not hang in there hot. Higher temp capable pads tend to be soft when cold and you may not be happy w/o booster.

As far as vacuum for a booster, you are not far off. My junk ran 9" vacuum before idle tuning. With more advance and mixture dialed in, it made 13" and vacuum boosted brakes work fine.

My 70 Duster 340 had manual disk brakes and they worked great

Thanks ALL

Anyone have a good P/N and source for the correct master cylinder and proportioning valve for my application? (1972 Cuda with stock 4 wheel drum brakes adding 1973 Cuda stock style front MANUAL disc)

"The brake answer man" seems extremely knowledgeable and stated he has the best available offerings? This board has allot of experience and knowlege so input is always welcome

I used a 2-bolt Master cylinder from an early 80's Aspen I bought from NAPA and installed Dr Diff's 4-to-2 bolt conversion bracket and adjustable pushrod.

I used a late 70s Volare MC so that it still had 4 bolts and it bolted right up.

I'm using a Raybestos MC36406 as was recommended by Dr. Diff when he sold me the rear disks.