The Felpro gaskets you are using are made to be installed dry. The teflon coating on the exterior of the gaskets is there to seal any imperfections in the intake or head. Silicone based sealers are not needed.....however if the surface of the head or intake appear severely pitted, a thin layer of silicone may be beneficial. Ask me why...
. I was trained by FelPro representatives in my olden days as a auto parts salesman.....