Answered on the Othar Forum, but I guess I can repeat it here...
You need at least the FD-specific Torrington bearings and spacer.
It's easier to use the FD front counterweight and "load" washer.
That load washer is designed to work with the larger Torrington bearing, and the FD front counterweight is machined to accept the larger load washer.
Making it work with the S4 rotors is going to be a pain in the ass...
-Ted