'70 Rear Drum-to-disc Conversion - Replace Master Cylinder?

[RavenBlack1]

Dear Stagnetters -

I'm currently in the process of tackling a rear-end conversion on my '70 Sportsroof. I'm going from the stock 9" rear-end to a Currie 9" (http://www.summitracing.com/parts/cur-fdm6466x/applications/) with 31 spline axles and the late-model large bearings, and I am changing out the rear drum brakes as well.

I have no problem upgrading to the 11" rear drums (http://www.summitracing.com/parts/cur-65450/overview/), but considering the price of a single-piston disc brake conversion, I'm considering going with an SSBC kit (http://www.summitracing.com/parts/s...year/1970/make/ford/model/mustang?prefilter=1).

I already have disc brakes up front, but my concern is if I make the rear disc brake conversion, I will have to upgrade the master cylinder / change out myriad other mysterious, unknown parts...

What all would I have to convert to make the change from rear drums to the single piston system?

Any input is greatly appreciated.

Thanks!

 

[rbohm]

the master does need to be replaced with one designed for a disc/disc system

 

[jetmech807]

Proportioning valve also I believe.

 

[WorldNet]

Hey did you ever resolve this issue? I converted to rear discs and the standard power MC was just fine after the rear brakes were bled. The calipers were single piston and the MC/booster unit came as a stock replacement.