That is why I said it was "popularly known as a C5". The C4 came out in 64, just like the date code C4 suggests. The tranny he has is popularly known as a C5 because it is a beefy C4 that was introduced for trucks in 65. The version that Ford officially named "C5" came out in 81 and was closer to a C4 than the original C5, but some idiot named it "C5". It should have been called "E1" by Ford's own system up to that date. Ford may have called it C5, but to me and most tranny guys I know, it goes C4, C5, E1... To heck with Ford's brain fart in 81. C6=66 E4OD was engineered in 84 so why shouldn't a 65 tranny be C5? The E1 is closer related to a C4 than the C5.
Yup, read an article in that line, where the C4 was made originally in 64, and beefed up in 65 for bigger engines, but everyone kept calling it a C4 instead of a C5.
The only thing that changed was where the bell housing bolted to the tranny - all the internals remained the same - no beefing up of anything. I have been in the tranny business for 35 years and I don't call any C4 a "C5" and there is no "E1" and the C5 was introduced in 82 not 81.
I was told by a tranmission guy back in the 70's (when I had a 69 Ford van with the heavy duty C-4) that the pan fill had better internal parts than the car transmission. Don't know if that was true or not as that C-4/5 crapped out every two years. The 80's C-5 only came with the 164 tooth bell due to the lockup converter. Y'all are both right about the C-4/5 designations.
Let's just end this arguement quick with overwhelming evidence from one link... Lots of posts, many more links, lots of pics, and race c4/c5 tranny builder interviews all in this one mega-thread. Excellent reading by the way! http://www.fordmuscle.com/forums/c4...hread-text-edited-way-long-version2_9911.html
