Well this is a bit odd, I thought I'd gotten just about every thing there is to get in this game, but I guess not. The only hidden head part that I know of is in the Destroy Berzerk MT's mission, but it's not the head your looking for. I looked around the net to see if anyone else knew where it was, and they made menssion of it, but never told where it was. So, I can't really help you with it. I'll post a couple of my fav. cores up here later when I get home from work, so you can check them out, and see how you like them.
Sorry bout that.


Later all,
Darkraider