VHT makes a header/exhaust coating that works well if applied according to their instructions. I've used it on a Honda exhaust and it's holding up well 1 1/2 years later. I got some from O'Reilly auto parts. The application is kinda a pain: spray, bake, cool, bake again, repeat 3x, and so on.
http://72.10.43.141/high_temp.htm
