I've used the same process and parts since the 80s with stamped and cast covers, all engines: Cork gaskets or whatever brand you can get, clean the covers to get off any oil even from your skin. I use brake clean on a shop paper towel. Use 3M weatherstrip adhesive and glue the gasket to the cover making sure the holes are lined up properly. Clean the head flange the same way. Leave it totally dry. Install the cover, and use a 1/4 drive wratchet and just your wrist to tighten them. I've found overtighening, overzealous use of silicone, and oil residue are the most common causes for leaks. I get a lot of re-torques without needing to replace the gaskets.
