69 and older have the same spline as 70 and up, but the column diameter on the 70 and up is a lot larger due to the key in the column. this requires a larger adapter "can" to cover the column internals. i installed a small diameter C body wheel on my 74 D100, and it fit perfectly. i also installed said wheel [one identical to it] on a 72 sattelite. same great fit. splines are the same as had been mentioned between column types, straight to straight, and saginaw tilt/tilt-tele columns. 69 charger wheel to 64 barracuda [straight columns], 64 barracuda to 48 plymouth [!], same spline, but the 48 column diameter was way smaller than the 64 barracuda, necessitating a custom fabbed cover. just some of the many swaps i have preformed in over 50 years of playing with these things.