well, since the thread's back-
pulled head at 179k due to a failed black plastic water pipe,
and the majority of the chain components are fine.
The vertical rail on the tension side, however, had lost adhesion to the metal-
how much longer it would have gone is anyone's guess.
And all the solid plastic tensioners were very brittle.
So my take is that they probably would have come apart pretty soon...
I'm replacing all the plastic, and leaving all the metal (except the tensioner)
because, well, the car was $600...
fwiw,
t