Sallens,Do a Google check to confirm this. The C 9B is I believe C is Fordspeak for anything from the 1960s. So a "C" and 9B is 1969 February. This make it a 24 spline input shaft C4. This is not what you want. Keep looking. Any C4 will bolt up to either the Flat O matic or other adapter. Pete
Want to add if you want a 70 or later C4 with the 26 spline shaft ( and you do) look for a tag with
D0 = 1970 or D1 = 1971, you get the idea
The C4 is a very easy autobox to rebuild and requires no special tools. Go online and check out Badshoe for a video on rebuilding a Ford C4