red spray gasket adhesive
Permatex also makes a red spray adhesive that works well for adhering the gasket to the valve cover, and the best part about it is that it goes on about hair spray consistancy, so no worries about it clogging anything up later.
FWIW, When I drove my Kadett back to NY from SD with the 1500 motor in it, the rocker studs were worn out and the adjustment nuts kept loosening up. This meant I had to stop (every 50-80 miles or so at one point) and adjust the valve lash on the side of the road, until I got totaly fed-up and double nutted them. The standard rubbery FelPro valve cover gasket that was on the car was reused for the whole 1400 mile trip, for a total of 14 times removed and reinstalled. Even after I got home, there was almost no leakage from the gasket. I took the time to send them a nice thank you card for that, it amazed me so much.