to make the radiator hard coolant pipes and CAS look a lot better. Degreased everything, prep'd with Bulldog adhesion promotor and used a good metallic silver spray paint (has flecks of silver). As a test -- finished the CAS with hi temp clear coat to see if it helps any? So far, all parts have held up well with no oxidation or discoloration.
Can't say how well this would hold up on the plenum? But if I was doing - would at least prep with a good power sanding/buffing to get the surface less poc marked and more uniformly even.
PS -- A few months back read a posting that clear coat on engine parts can turn yellowish after a few years of heat. Knowing this (now) would probably lead me to not clear coating any parts that couldn't easiely be removed for a re-do.
