Technical Drum Brake M/C

On my truck I have drum brakes all around and obviously a drum brake m/c. I want to switch to front discs and possibly rear discs down the road. Can I keep my m/c if I only go discs in front with a residual valve setup? Do I need a different m/c if I decide to go with 4 wheel discs eventually? and do I still need the residual valves if I go with all discs. Also, it is power assisted by the way. Thanks

 

Loaded question here. Most say use dual master. Master above the frame no residual
valve. Disc drum adjustable proportional value to the rear. My take why not use a dual. A lot of them will work with disc drum. This is only my opinion.

 

front disc you can use your master but you will need to remove check valves or your discs will lock. for all disc I'd change toa corvette for more flow.