I use Fel-Pro molded silicone rubber gaskets. They are made from high temp silicone rubber and have a solid steel core. They are reusable and they are the only gaskets I have found that don’t need to be tightened up all the time using factory original aluminum valve covers. There is no need to use any extra sealent with these gaskets. Jegs has them but they are way over priced from them. I ordered my set from a local parts house I have been dealing with for years for less then $30.00 3 years ago.
This is Jegs link:http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_198910_-1