Here is the list of parts that I accumulated to change my 64.5 mustang from non-synchro 3 speed to a green dot C-4.
1. Auto tranny shifter, complete with T handle, mounting base and bolts;
2. Shifter indicator light, power wire and ground;
3. Auto tranny shifter bezel, with mounting screws;
4. Auto tranny shift linkage (z shaped bar that connects shifter to tranny gear selector arm;
5. Neutral safety switch;
6. Neutral safety switch wiring;
7. Tranny kickdown wire for engaging passing gear;
8. Engine shim plate (goes between engine and tranny at top);
9. Lower tranny inspection plate with correct mounting bolts;
10. Torque convertor with correct nuts;
11. Flex plate with correct bolts;
12. Auto tranny with correct bell housing and mounting bolts
13. Auto driveshaft with correct input yoke and two good u-joints;
14. Rear pinion flange for rear end (from car with auto tranny);
15. New U-bolts for rear end to hold rear u-joint to new rear pinion flange;
16. If converting car from stick to auto, you may want to consider replacing the 3 pedal (gas, brake, clutch) assembly with a 2 pedal (gas,brake) assembly.
I did not have to modify anything, everything just bolted in, but it takes time and patience.
I do not know if there is a difference in parts between the 2 speed and a regular C-4, perhaps someone else can provide that answer.
Keep us posted.
Thanks.
Kurt.