Performance rocker covers cast from aluminium. The rocker cover is made of aluminium because aluminium can conduct heat better. The rocker cover also has�cooling�ribs for extra heat conduction. Because of the material and the cooling fins, the cylinder head remains better cooled.� In addition to better cooling, the rocker cover also has a classic look. The appearance on the�engine�block can be clearly seen on photo 4, 5�and 6.� With the valve cover we recommend to use the valve cover gasket, install them the other way around. Note! These valve covers do not fit the Burton, unless the front has been modified.