If your transmission is like mine, then the cover plate has a small vent hole in it towards one end. I can't remember if the bolt holes are asymmetrical so the cover goes on one only or not. Maybe someone can chime in and clarify that. Personally I think there are better gasket materials than cork out there nowadays, but if that is what they gave you then I would use some kind of gasket sealer and avoid over tightening the bolts. You don't want to squeeze the gasket out of place.