Bretto...if you are still watching this thread, the radiator paint is thinner than the high heat. Almost translucent. Dissipates heat better. Eastwood has it in spray cans. No problem painting the fins with it.
Too late. I used some semi-gloss high heat paint from the local shop. I didnt spray it directly straight into the fins but at a good angle perpendicuialr to the fins so that only the front edge of the fins got color. Then I did the body of it as well.