I suppose I should have the right flywheel, but I would expect the 2.5 flywheel to be heavier than the 2.2 flywheel, and I can't see how that would cause any harm to the clutch.

I am quite sure my backlash is in the clutch. If I put the clutch tool in the disk, I can rotate it back and forth about 3/4 inch. Oddly, the free play is inside the center of the disk where I can't see what is happening. The visible springs seem to be OK, and I don't see them move at all. The driveshaft and differential seems quite tight, which is what I would expect since the car only has 130K on it.

Before I posted this, I searched for "clutch" on this forum, and read all the threads I found. I couldn't find much information about this problem, and I suspect it is relatively rare. I can't imagine what kind of abuse could cause this problem, although I did use this car to teach my teenage daughter to drive a stick.