I glue the cork valve cover gasket to the cover with 3M weather strip adhesive. The gasket stays put and the cover can be removed and replaced many times with no leaks.On all other gaskets,including the intake, I use Hylomar gasket dressing.It makes for a no leak joint and the gasket can be removed easily if necessary.Some 261/235 head gaskets have a slippey coating that won't take a sealer very well,use em dry I guess.Otherwise , Hylomar or a typical dedicated head gasket sealer like the copper stuff or even aluminum paint works fine.I never use silicone type sealers on engines,except occasionally on a thermostat housing.Seen guys glob on the silicone and sometimes it finds its way into areas it doesn't belong.Permatex "The Right Stuff" is a urethane based product, I believe, and just like the stuff factories use on new engine gasketless joints. Unlike silicon,its ready to go immediatly.Make sure all your sheetmetal parts have straight flanges so they press on the gasket equally .
