What is the correct master cylinder for manual disc

This comes up alot, and about 2 years ago I needed to replace my mc on my 67 Barracuda with the KH 4 piston manual brakes.
After alot of research, I bought a power mc for a 71 to 76 Dodge.
It looks more like greendart72's mc.
It bolted directly on, the pedal is much easier, and it stops better than ever.