Steel tailgate huh, thats a tough one, Try ECCs' link page under El Camino Retailers for starts. Also check Ebay, I've seen a few there from time to time, there's a guy on Ebay that goes by makmontes, if you can find him on Ebay selling any of his items you'll be able to contact him. He deals in a lot of used parts. Expect to pay quite a bit for a steel tailgate in good or better shape. I don't know of anyone including GM that carries new ones any longer.