I must find those bloody worshop updates for this and solve this once and for all. The C4 is the early version of the C10 yes but thats all. The C10 has bigger bands and clutchs as well as differante front pump housing. It is stronger than the C4 because of it. Its like saying a turbo 350 is the same as a turbo 400. They are two completly differant box's. Dont you wonder why when you order parts for the C4/C10 they ask
you for the year or date of manufacturer, thats because of the two differant case's ring your local auto work shop and ask them and see what they tell you.
When I browse thru a catalog of you-beaut accessories for this tranny, they only list the C4 (with variations). No hint of the elusive and mystic C5/C6/C9/C10/C-U-L8R.
Spot on, there are 3 versions of the C4 (windsor, 6cyl and cleveland), all have significant differences, but ALL are recorded by Ford as C4's, you just need to know what vehicle it came out of to know which one it is, or what the part number is on the box!
I have NEVER seen any official Ford document that mentions C9 or C10, only C4.
I have only ever seen C9/C10 in aftermarket books and publications, i believe the notation C9/10 was made up by tranny joints for easy reference however in Ford speak they are all C4's
F6: the fastest factory 4 door falcon in the world!