That's for you to decide,.. based on your experience...
New spline shaft, pulley, plus gaskets will cost a $100 or $200...
... and you might booger the assembly (I would)...
I would never attempt it... if mine goes, I'll locate a low mile engine and start over with newer everything...
JMHO... I'd make it super tight and keep an eye out... if the splines wear too much, have it welded in place...(you'll never be able to get the belt off from that point, but it can last 100k miles)...
Then, when the belt finally goes, just buy a new engine...
It ain't the right thing... it's just what I'd do...
...
PS.. I can't remember if you have to remove the pulley to replace the stator...
Anybody?...
PSS.. actually,.. you could replace the belt,... by grinding away about 30% of the outer pulley edge... just enough to get the belt past the stator cover case... not sure if that would be too much to keep the belt in place for use... but it might stay... might be fine...