Slotcar

I'm replacing my valve cover gaskets after adjusting my valves...I used gasket cover remover etc... This residue left over after the gasket is removed is difficult to remove. How clean does this area need to be? Is this residue a burnishment or is it a silicone material that will meld with the new gasket material...?

Should I re-torque the barrel nuts while I'm in there?

Peter Zimmermann

slot: I would scrape the gasket surfaces with a single edged razor blade. From what I see in the pic you should be able to get that surface much cleaner. Always use new blades to avoid scratches!
Pete