(EDIT: ^^^ rothfm beat me to it.. lol)
Nowhere near an expert here, but when I looked it up trying to find an answer for you....
I was a little surprised to find it seems there isn't a "Head Gasket" as one might expect.
It would seem based on the diagram that there are O-Rings that go under the cylinder head..
(#33 in the diagram here:
http://www.iboats.com/Cylinder-Crank...iew_id.1555185 )
Diagram makes it look like there are grooves in the head that the O-Ring sits in and that's the seal..
I've never seen that before, but that's what it looks like to me..
Maybe some more research on that would be in order to find out what "Kind" of head gasket is needed?
Going to follow this one, as I'm interested now too! lol
For what it's worth...