Just a note to clear things up a bit. Ford did not call their transmissions C4 or C6. The terms were coined by the aftermarket because the parts on the C4 carried a C4 prefix and the C6 carried a C6 prefix. Anything Ford starting with a C4 swould indicate a part first us3ed in 1964 ie. C represents the 60's decade and the 4 denotes the year first used in that decade, thus C4. The C6 came out in 1966 thus the prefix of C6. Ford uses a prefix, basic number, and suffix. The prefix will tell the first year of production and car line C4AZ indicates 1964 Full size Ford. C4OZ would be Fairlane , and TZ for truck, SZ for Thunderbird. and so one. The basic part number is one ford assigns a part and the number indicates what system it is for 7A000 would be automatic transmission 7000 would be manual trans mission and 9510 would be a carburetor. The suffix would indicate a change or revision of the part. Sometimes like hub caps which are 1130, every car and truck line uses that same basic number to identify a hub cap. But, since all the hub caps are different, you might have a suffix anywhere from a to z. Ford parts are a language which makes great sense oncw yo learn it. And like I said, the aftermarket caught onto the C4 and C6 prefix and Ford picked up on iot a few years later and used the terms to identify those transmissions. I hope I wasn't too wordy in explaining things.
The Jalopy Journal
