I have a leaky Rocker Box gasket, and it appears I will need to remove the valve cover and gasket to get to it. The rocker box gasket is cheap--the valve cover gasket is not that cheap. Can I reuse the original, non-leaking valve cover gasket, or is it a one time use only gasket? Would rather only do this once, instead of going back a few weeks from now to do it again. Thanks.