I don't recall, but the 914/4 splines are the same as a bug, and the same (except for length) as a Bus/T4 CV. (The T2/T4 CVs are wider)
A common "fix" for the unobtanium (no longer available) 914 CVs is to time-sert the 914 CV flanges and use common T1 CVs/boots/etc.
There is also a place that drills out a T1 CV for the ~13mm roll pins, so it is a drop in replacement.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.