I would think 63 is the same as my 65. I used the Breeze master cylinder and vacuum booster. For that, the critical part you need is "stand-off brackets", from all A-bodies w/ power brakes. Make sure it includes the lever arm w/ brake rod to your pedal. I got the brackets off a 73 Dart. I had to rat-tail file the holes a bit because the 4 hole mount of the booster is a slightly different metric pattern.
I haven't driven the car yet, just bleed in the lines, so can't claim my approach works. My pedal has too much "lost motion" but maybe just in the shoe motion. After the new shoes seat and adjusters kick in it should improve, or maybe I need to adjust the booster to MC rod. I put the MC on an identical-looking booster from an Intrepid because the later was already mounted when I found it's longer MC and slanted reservoir wouldn't work. A booster adds weight and size, plus you have to lift it to remove a V-8 valve cover. I also have an adjustable proportioning valve for the rear because I want to change to front disks later, which is why I needed a booster.
If you stay all drums, you can skip the booster. You then must mount a modern 2-hole master cylinder to the older 4-studs at the firewall. Mopar Performance makes an adapter plate, but ~$70 which is more than my junkyard solution, though a whole lot easier. You can also buy the MP master cylinder, but it looks the same as on most current cars. Ideally, you should compare MC piston diameters. Smaller gives you more force, but also more pedal motion (don't bottom out!). I didn't do any engineering. I just figured that my Dart weighs about the same as a Breeze it should work. I'll know soon.
