[SwedishDoomGoblin]

Makes sense to replace the serpentine belt for only parts cost at 60k if it is in fact the crank seal leaking.

100%. You're coming up on that anyway at maybe around 80K I believe. Might as well reset that clock. Belts are cheap. Destroyed valves are not. Not that you're in danger at 60K, but at 100K you would be.