Another C4/FMX question

[hoss73ford]

I have a '67 Galaxie. Did they change the rear splines during the late 60s or 70s???

I know they changed the front spline count on the early ones I think from 24 to 26 and the older torque converters are hard to find whereas the 26s can be bought new.

The car will be in someone's garage and I don't want to find out the hard way that the driveshaft won't fit if I put a later year one in.