BESTgasket is the world's premier manufacturer of gaskets for vintage and classic American cars and trucks. BEST Gasket valve cover gasket set for 1956-1966 Dodge and Plymouth models using a 277ci, 301ci, 303ci, 313ci, 318ci, or 326ci "POLY" V-8 engine. P/N 20018E. BEST Gasket is the leading name in sealing performance in the restoration industry.