HEH S toploader 4 speed

[6s1432]

I just picked up this transmission. Was it ever used in anything except a very early 1964 hipo mustang? Not sure what to do with it. Mark

[S7MS427]

Mark, My toploader tag application chart on my website lists this as a close ratio box (P/N C5ZZ 7003-E) for a '65 Mustang before 8/20/1964. No other application listed. Hope this helps.

[JohnSlack]

Mark, My toploader tag application chart on my website lists this as a close ratio box (P/N C5ZZ 7003-E) for a '65 Mustang before 8/20/1964. No other application listed. Hope this helps.

Is it a 25 spline output shaft transmission?

[S7MS427]

John, No, HEH-N (C5OZ 7003-N) is listed as a 25 spline CR gear box for a 1965 Hi-Po 289 Fairlane, since no such note exists for the HEH-S transmission, that one must be a 28-spline unit. The information source is the Ford MPC. This chart is published on my website. Again, I hope this helps.