I'm putting a 250 from a 74 c10 in my 51 3600
my question is the clutch disk for a SM465 the same spline as the SM420 that's in 51 it has the torque tube

basically did they change the clutch disk spline, or would I need to go with a 67 disk that used a SM420.
And is the 67 c10 spline the same as the 51 spline