I am in the process of building a 1968 charger. The car has a power disc/drum brake setup on it. I bought a moser dana 60 rear-end with disc brakes. The engine is a 440 block and the brake booster is a dual diaphragm. What master cylinder do I need for this setup?

 

There is most likely a spring on the rear drum brake side of the Master to hold a few lbs of pressure on the wheel cyl SO you would have to remove the fitting that is inside where the brake line goes into to remove the spring Or send it out for a rebuild or search parts books for a replacement

 

Would that be the small rubber and spring behind the residual pressure valve?

 

Once all that is sorted? It does'nt hurt to put a 2# residual valve inline to the rear brakes to firm up the pedal.

 

Thanks for the tip.