Finally I'm back at it. I want to put disc brakes on the front I have already put a late models rear end and it a 9-inch Ford and I am going to leave the drums on it I guess the question I have is it really necessary to change master cylinders and add proportioning valves and all that nonsense

 

If you really want the braking system to function properly, yes. I'm sure you know, brakes are the system to never go cheap or only halfway on. I did discs on mine, used a Corvette MC with remote fill under the floor

 

Yes, it is important to get a modern master cylinder with a proportioning valve that is designed for rear drums and front disks you may also need residual valves for the front disks and maybe the rear drums.

Designing Your Brake System