One new Borg Warner brand 1905cc clutch cable, part number PR005 or 644 423 401 01.  This fits:

Porsche 356SC (741 transmission) 1964 - 1965
Porsche 356C (741 transmission) 1964 - 1965
Porsche 356B (741 transmission) 1962 - 1963

There are three different cable lengths used so be sure to check your old unit (1905mm, 2015mm or 2060mm).