Thanks to all who responded with suggestions for how to fit a new
27x8.5R14 in the spare carrier of my '89 Syncro.  I finally took the
brutish-force approach of removing the springy steel rods that run over
the top of the tire (which also form the carrier hinge) and bending them
up and around to accomodate the wider tire width.  Took about an hour to
remove, bang around in the vice w/a 10lb hammer, and reinstall.  Really
wasn't as bad as I thought it would be.

Now I can get the tire in the carrier and latch it up on the plastic hook
with minimal effort, then thread and fully tighten down the standard
length retainer bolt.  Still hope I don't ever have to do this by the
side of the highway...

-Steve