I used some lead substitue actually, but I don't know how similar to lead it really is.
But still, the first time with the leaner jetting and hotter plugs they looked real bad. They were all chalky.
Now they just look like they weren't even used. If it wasn't for a slight change in texture on the ground strap I could put them in a box and say they were new. The porcelin was SPARKLING.