Back in 1989, I put a SS brake kit on my '65 coupe. The kit had the 4 piston calipers in the front and single piston T-bird calipers for the rear, but no master cylinder came. I bought, if I remember right, a'67 dual reservoir front disc rear drum master cylinder for $25 from a place like NAPA. To make it 4-wheel disc compatible, I removed the inner residual pressure cone from the front port (rear brake reservoir). It worked fine, I didn't use a power booster either. I did have an adjustable proportioning valve that I plumbed next to the drivers seat so I could adjust the pressure while driving (only had to make 2 adjustments from rear lock up and it was set). I had been told this trick by someone in the brake industry, but can't remember who. Verify this before you try it by asking someone who knows mastercylinders. Some guys discourage this so they can sell you a new more expensive one.