Use 3M 8001 Weatherstrip adhestive and glue the cork gasket to the valve cover. Make sure you follow their directions.
Check the area where the intake meets the head - if it isn't smooth or looks like there is a void there, seal it with some RTV.
Lightly
oil the cork valve cover gasket and install making sure you don't tighten it down too hard.
You will be able to remove and install the valve cover many times before you need to replace the gasket.