Recently I ended up with several boxes of spark plugs that I do not know exactly what they fit but surely lots of Chevies! They are made by Firestone Supreme with numbers like E40F-F130-M120CF(18mm)-M80(14mm)M100-M100C-M40CF-F100 and a couple others. I would sell these for couple bucks a piece as I cannot use them and to help someone out. They are still in origianl box. Let me know if you can help or can use some of them.