I used this KBS motor coater when I painted the engine (in place) in January. The Pontiac Metallic Blue looks pretty good. They also have Pontiac light blue available. After a few miles (less than 20) I do have some slight discoloration on the exhaust ports on the head and a little less discoloration on the center ports of the intake manifold.
Not sure if any of these paints stand up to the temps without discoloration. (on cars that are actually driven)
I also used this Xtreme High temperature paint on my rusty old exhaust manifolds. (used cast iron gray color) They look really good with no discoloration to date.
Overall I am pleased with the results.
http://www.kbs-coatings.com/Motor-Coater.html
http://www.kbs-coatings.com/XTC.html