[Rallye Sport]

If its the new style re-usable rubber gasket then it shouldn't need a sealer. I've heard mixed reports about these leaking and am about to find out myself as I'm using one on my new engine build.

With the rocker cover, take it back to bare metal if you can and use the matching primer, it makes a massive difference in the end result. If the plastic spark plug clips are still there be careful removing them as they're unobtainable now. Gently lever them off from underneath with a screw driver and put them in a safe place.