interchange for the 1964-1966 sedan master cylinders? I am referring to the one with the split brake system ~ less power brakes tj1852 I used a Wagner F56193 on my 64 Commander (without power brakes). It required no modification. It works perfectly, and it even has the old-style bolt down cover. Tim r1lark For my ’64 Commander with manual drum brakes/split system, I used a Raybestos MC36237. This is a 1” bore M/C used on almost every drum brake AMC (manual and power brakes) car from ’64 thru ’76. Note that this car already had a dual master cylinder from the factory, but I chose to use an easily found replacement master cylinder versus rebuilding the original. Paul