Slant 6 Aluminum Performance Head

Howard Davis made a "one of" billet aluminum head for a slant six. There is a post and pics, somewhere over on dot org. He is/was running it on his engine. at the time it was posted, it was stated he would not do another one. That is all I know about it. There are a couple of "factory" aluminum slant six prototype heads out in the real world, but I don't know who has them.