These old engines like gaskets, big thick asbestos/paper gaskets. I'm not sure silicone was invented when these inlines were made. Newer engines like Nissan, etc. have tight machine work & a groove for silicone sealant only on oil pans, timing covers, etc. You can use a smear of silicone on gaskets if you like or use products like Hylomar, Gaskacinch, Permatex. Brian