Copper. The cheapest ones they have

I noticed today the part Champion part number is listed on a sticker under the hood.

 

I can't seem to locate any champion truck plugs. Checked auto zone-napa-advanced auto nothing.

 

Another thing that will make life easier when changing plugs is to remove the EGR tube that runs directly over the passengers valve cover. Remove the 2 8mm bolts that secure the tube at the valve and one clip at the intake, behind the throttle body. The gasket is reuseable as long as you dont tear it up, but its a tough fiber type gasket, I have done many and never torn the gasket