Our starboard side exhaust manifold had a crack in it. We had it welded and then where the gasket goes wasn't a perfect flush fit do to the weld. It may not work but we have not been able to find one for the v6 so we thought we would give it a try My question is what type of permatex gasket maker do we use with the regular gasket. We have been told to use the regular gasket then put a form a gasket or permatex on either side of the gasket so it can form a seal. Can't figure out which permatex to use their are many types. Their is even a copper one we were told to use but then someone else said they wouldn't. They were not all boat people but being you all are we would love to have some advice on this please. Also it looked as if one of the four holes or channels on the manifold was blocked almost looked welded closed. It wasn't rust or anything but is that normal or should all four be open it is where it meets with the riser elbow. Is it going to damage our engine if the weld dosen't hold. of course if we noticed the exhaust leak again we would stop immediately. Thanks in advance for the help.