My mechanic bought and installed a Athena gasket kit for a Honda CB750 SUPER SPORT 76-78 kit P400210850701. I have a 1975 Honda CB750 K5 are the gasket kits similar would a 76-78 kit work for a 75 K5 super sport? There where a few extra gaskets left over but I believe there for the Hondamatic? There are two of these rings left over what are these for? Exhaust gaskets?