Moulded to shape not cut to size from flat commercial stock
No labour required for scraping off old gasket and sealant after initial installation
Low torque requirement thus avoiding valve cover distortion
These premium silicone gaskets are produced using modern measuring equipment (CMM) and CAD programs. The Proprietary Formulation of the silicone yields the best Shore Durometer for the application. The result is a permanent gasket that provides a total oil control with modern oils. The gasket has the feature of being able to be removed and reinstalled multiple times without being replaced. A thin coat of RTV on one side of the gasket to fixture the gasket is all that is required..once.
Cork and paper gaskets are cheaper, but labour intensive and not equal to the challenge of containing modern synthetic oils. Rubber is better but does not have the malleability of silicone and also degrades and hardens over time