Are you going to have a shifter on the column? Be sure to get a C-4 that is a column shift as the selecter on the trans may be different. I did this conversion in an early TBird and used the TBird shifter (had a Fordo). The trans, which was an 80 unit, had the correct shifter for both floor shifter and column shifter (one arm up, another down)..
One thing I ran across on the Flat-O kit - the starter had to be spaced out the width of a standard flat washer (get three that all measure the same) as under certain conditions the teeth on the starter would very slightly hit the flywheel.
All in all, the Flat-O kit was great.
54 Victoria 312; 48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ