I used to have the old mopar performance chrome valve covers (the tin model, not cast) and would just use the cheap cork style gaskets. They were fine for a one time use. I later upgraded to the Mopar Performace Cast Valve Covers and started using the Moroso blue gasket with steel core. Been on the car for close to 10 yrs now without any issues. I usually check the valves twice a year or so, so they have been on and off many times.