1997 Deville Timerserted at 130K miles. Not back on the road yet, but the insert kit worked very well.
I think the head gasket was failing some time ago. Had a missing cylinder in the morning that would clear after a minute or so of idling. I think the deathblow on the gasket was when the water pump belt popped.
Hoping to squeeze at least 20K out of it before I let it go.