67 coronet rt pwr drum brake to disc conversion

[67 R/T]

I've decided to rebuild the pwr drum system that is original to my 67 rt instead of converting over to an aftermarket disc setup. I sent my original Midland booster off to Wayne the brakeman for rebuild and have begun refinishing the front drums. What I just found is that a few yrs back I had actually purchased a disc brake setup for this car and then put it away out of sight. Would it be possible to use my restored drum brake booster/mas.cyl under the hood but install the shiny new disc setup behind the wheels?

 

[Propwash]

A Power Disc Brake Booster has a different power assist ratio vs. a Drum Power Brake Booster, meaning the pedal swing/movement applied produces a different amount of assist between the two. So....you're gonna run into problems. Don't expect factory type disc brake performance and I couldn't tell you if it would be safe to use. After speaking with several of the big aftermarket brake companies and a few Brake Guru's, the answer to that same question you asked was no...no...no!!!
As far as your master cylinder, you need to make sure the Master cylinder has a built in residual valve or you'll need to install one somewhere inline for the rear (cheap/easy). Most Master cylinders for a disc brake car have them incorporated right in the unit. Also with drums, you would have a metering block, some say you can get away with that in a conversion. Myself, I would definitely recommend proportioning valve.

I went through the same thing with my 69' Roadrunner (Power drum to power disc). I ended up having to find a Factory Bendix Power Disc booster. Bolts in the same, linkage arm and rod is the same, just had to buy a 1 1/8" Bore disc brake master cylinder to go with it. Master Cylinder was easy to find (rock auto). The Booster on the other hand was quite a hunt.

Hope it helps...