Manual Disc/Drum Master cylinder and stock manual push rod

Hello all,

I have a 74 Duster with manual drum brakes all the way around. putting manual disc up front and need to find a master cylinder, heres the ??? All of the disc/drum manual master cylinders I've found have the 1-1/32 bore and I was thinking about using a cast iron master with 15/16 bore but am worried that the stock manual push rod will not work properly. I'm not interested in the conversion from Dr. Diff but was wondering if anyone has successfully utilized one of the cast iron 15/16 masters with the stock manual push rod. If so, which one did you use and what if anything did you have to do to make it work properly?

v/r
Ron