Matts right---for any exhaust manifold parts, use 1200 to 1500 degree paint especially made for that purpose. An engine block, heads, and intake manifold does not get hot enough to burn paint off. I have painted them with enamel, one-shot sign painters enamel, spray cans of engine paint from auto suppliers, even high end base clear paint, some sprayed on, some brushed on, and it all stayed on. Just be sure to degrease and clean the engine very well before you paint---sand everything with light sandpaper, steel wool, and /or Scotchbrite pads before you paint.