I am going to say no here.---The 78 models used the big 30 cube powerhead and may have a different spline in the crank.---Various places where you can check the driveshaft part numbers.
On the other hand.... could be useful going back quite a ways. May be mistaken, but think that 25 driveshaft was used from the late 50s up into the '70s, 18s, 20s, 25s(?)