'90 80q radiator - is failure inevitable?

[Chris Darringer]

I have a '90 80q with over 180k miles on it, and I was planning on having
the timing belt and all of the (still original) radiator hoses replaced.  I
have read quite a few warnings from listers regarding the cracking of
plastic radiator necks, so I was thinking about getting the radiator
replaced as well.  As anyone had one of these radiators last over 200k
miles, or is failure inevitably lurking right around the corner?  Maybe
there was just a bad batch of radiators produced one year (ha-ha)?

Is the heater core equally prone to cracking at this time?  If so, maybe I
should set up some kind of heater core bypass now?

While I'm at it, should I replace the expansion tank?  Anything else?

Thanks for your time,
Chris
'90 80q