INSULATOR PLUG TYPE INTAKE MANIFOLD ATC70_78to85 C70M_all (sold_each) (84S) THIS IS AN OEM RING, INSULATOR FOR INTAKE MANIFOLD ATC70 78-85. THE BOLT THAT HOLDS THE CARB ONTO THE MANIFOLD GOES THRU THIS. WITH OUT THIS THE HOLES IN THE STOCK MANIFOLD ARE TOO BIG. THIS ALSO HELPS INSOLATE THE CARB FROM THE HEAT OF THE HEAD AND MANIFOLD.