I've had my LS for 50K miles... Now, I date code the COPS, ie. 12/10.. Then I know the new from the old. When an old COP fails and is it in a hard to reach location, I swap the cop from an easy up front location to the rear and try the faulty cop up front. I have also went to copper spark plugs and they seam to last longer than platinums. My #8 goes out every few months and has water in the spark plug hole. It used to be full of oil, but I swapped valve cover gaskets and that stopped. I don't think the quality of the cop is anything compared to the SH#T design of the motor and quality of the VCGs.. In 5 years of ownership all of my COPS have been changed twice, and the original factory ones also failed. I carry spare COPS, plugs and a wrench in the trunk.. I used to carry my scan tool when it was real bad.