Adjustable brake push rod?

Realizing this is an old thread, but here goes. I have too much throw in my break pedal and its screwing up the switch. Brakes were converted to a dual reservoir MC. The manual shows a stop but I don't believe the MC had threaded holes for a stop.
1966 dart. Was a 273 car, now a 318.
If I use a shorter push rod, will it pull the piston too far out? Will I have enough throw?? Any help us appreciated
Jim