Tim, I like your idea.  On the surface it make a lot of sense to me.  I'm
not yet intimately familiar with the plumbing of my '87 Syncro GL yet I have
a leak in my rear heater as I can smell the coolant when I turn the rear
blower on.  I will be dealing with it at some point.  I will be looking
forward to whatever you find out or decide.

By the way, I really appreciate all of the contributions that you make to
this group.  I lurk mostly, as I don't have much to contribute yet.  You add
value to my lurking.  Thank you.

Scott