Drum to Disk brake conv. no idea on the MC?

Here is a good website with part you are looking for.

MC36406 - 1973-75 Mopar A-Body Power Front Disc Brake Master Cylinder
Mopar Parts | MC36406 | 1973-75 Mopar A-Body Power Front Disc Brake Master Cylinder | Classic Industries

MD47277 - Adjustable Brake Push Rod
http://www.classicindustries.com/shop/mopar/parts/brakes/master-cylinders/push-rods/

MD2268 - 1969-75 Mopar A-Body , 1969-70 B-Body With Front Disc Brakes Combination Valve
Mopar Parts | MD2268 | 1969-75 Mopar A-Body , 1969-70 B-Body With Front Disc Brakes Combination Valve | Classic Industries