I've kinda given up on rec.autos.tech. They've lost interest in this issue.

An interesting observation I made recently: The problem appears to be
temperature-related.

We've had pretty nice weather since I had the tires and driveshafts done.
And that was when the vibration became apparent. Well, I've since noticed
that when the temperature cools off, the problem diminishes. When it gets
down to the 50s, vibration is less. As the temperature climbs, it gets
worse.

I'm going to sit on this for a while and wait for 80-degree weather, and
see if it gets even worse.

jim beam might have been right after all...it just *may* be an engine
mount...