After untold hundreds, maybe thousands, of valve adjustments on round track race cars, I've developed a few opinions. First, rubber gaskets don't cut it! They squirm around, and develop leaks, especially if the engine is run hard. I prefer good-quality cork gaskets. Fel-Pro is best IMHO. Use high-temperature RTV or better yet, 3M "Super Weatherstrip Adhesive" to glue the gaskets to the valve covers. (The NASCAR name for the adhesive is "Gorilla Snot") Don't apply any sealer between the gasket and the cylinder head. Use some spring steel "spreader bars" under the attaching bolts to even out the clamping force on the valve covers and prevent dimpling the covers at the bolt holes. These accessories are available at just about any parts store in the hotrod section. Mr. Gasket makes some good ones, but any brand is about the same. (These things were originally used on Corvair valve covers back in the 60's).
Snug the bolts until you feel all the slack go away, then tighten an additional 1/3 to 1/2 turn. I like star-type lockwashers under the bolts instead of conventional split-type lockwashers.
Jerry
