Re: Gasket cement
Unless it says otherwise in the manual I always use it on all gaskets, except the head gasket. The stuff I use is called perfect seal, left over from when I had in I/O and used it on the outdrive seals and boots. If you put it on the leaf plate gaskets be very careful not to get any on the leaves, I consider them the most percision part on an outboard.
Before you take my word on it wait for some of the more seasonsed motor guys to chime in.