Probably less than 5K on them, with cool sox and wrapped headers. The silicone insulator turned brown and brittle, they pulled apart easy, even one of the boots split in half removing them. A couple left the connector on the spark plug, was wondering why I was idling rough. Only 2 wires made it after removing them.
The last two still ohm tested under 40 ohms resistance, but I went back to my old stockers, good thing I never threw them out.