I have sprayed them with Copper Coat, and let them dry before installing. And have not had any problems. The 440 I just took apart, the builder used Moroso multi layer head gaskets, about.050 thick. They started the engine with no water, and ran it for 5 minutes. Then let it cool down, added water and ran it some more. He said it was to set the head gaskets. I never heard of that before. But the engine broke on the first run, so I don’t know if the head gaskets were going to leak
