I run the NX wet kit 100 shot and i just use the stock heat range plugs with no problems ..autolight 764's Copper. I have also heard of people running a colder heat range plug. But my opinion that it isn't needed with just a 100 shot. It is a MUST to switch to a copper plug though. But if you want colder anyway here are some Part numbers..." i could only find Motorcraft plug #'s" Stock heat range is AGSF32C and the step colder P/N is AGSF12C. Hope this helps.