Probably the first thing is to check the cover to make sure it is flat. It is not uncommon for the tin covers to be warpped or twisted.
Personally, I have done better with the cork vc gaskets. The rubber seems to have tendency to squeeze out. Generally I just put silcone sealer on the vc, place the gasket on the cover and let it set up a little, then bolt it in place.
Assuming it is a later motor due to your orange comment, there are enough bolts to tighten just one area if there is a leak. Good luck.
