I am refreshing my 78 750K. I have looked at pictures of engines painted to various degrees. I don't think I I am ready to go black on my particular ride, but it does look hot on some bikes. I know that paint on the lower end will stick if properly prepped, since they are painted from the factory. What Aluminum colored paints have you folks used on the engine barrels, and how is the longevity? I have no problem keeping the covers and valve covers polished, but the barrels are getting to be a real pain in the butt.