The first time I did this I glued the gasket to the valve cover with Indian Head shellac. That didn't work. The next time I glued it to the head, better, but still leaked at the front and back. Spent some time flattening the flange at the front and back on the valve cover, and then put a small bead of hylomar just on the front and back flange of the cover. I don't like to use this stuff with cork gaskets, but it did seem to stop the leak. hopefully when I take off the valve cover again, it will scrape right off!
