If you paint them at all, use radiator paint. It's got some heat-conducting properties so the brake can do its intended job of dissipating the heat. Use a very light coat. Drums are pretty ineffective at shedding heat anyway, so further handicapping them with a coat of paint that acts as a barrier to thermal conduction doesn't make a lot of sense. It's possible to reach a point called "brake fade" where the shoes input more heat than the drum or disc can dissipate. Lots of pedal, but no stop! A panic stop from 50 MPH with a normal-sized vehicle generates enough heat to melt a cast iron skillet!
Jerry
