Ed,
Do you run any kind of electronic ignition in your car ? Jacobs, MSD, etc. If so, I would recommend getting rid of the platinum plugs. I tried them with my Jacobs pro street and they don't work worth a darn. I called Jacobs and they told me to use the regular type plugs but never platinum as it throws off the resistance readings and will cause all kinds of problems. I changed about 5 years ago to Autolight and have never had a problem since and the car runs much better.
Ron
