MikeCan you clarify what engine is in the 62 merc? If it is a 221 0r 260 SBF then it is also a 5 bolt bell that Ford changed to a 6 bolt in 1964 1/2. The Master Cylinder is correct the C4 is the transmission of choice. I drove a Ford Falcon Sprint 260 and 2 speed FOM for several years as my work car and although never exciting it did work well.
If you change to a C4 get the right bell for the block. Pete