Water in CYL #8

water in the cylinders often comes from the exhaust manifolds being bad.   Certainly having an intake leak could contribute if the issue comes from a blown head gasket or cracked head.   I would check the manifolds though, they are not cheap, but are an important part of the cooling system.

Pictures can be uploaded by using the "post reply" editor, and clicking on the tree icon.   then name the photo, click next, navigate to the photo and click the link.   The site will prompt you to be patient, click OK and then the text string/code will appear in the reply editor.   Some people get it right away, others struggle, so you may have to try it a couple of times.

Study the old head gasket very close. If it failed you will see damage and signs of leakage.
If it was formerly overheated you can mic the gasket at many points and see exactly wear the overheat happened.
When overheat happens the head will swell in the hot areas and crush the gasket slightly.
When it cools off the head shrinks back to size but the gasket remains crushed in the overheat area. It may measure .004 small in the crushed area. Those areas will fail when you run the engine again.
The head may also have warped or
Cracked if it got hot enough.
Separately if a marine exhaust manifold goes bad it can allow water to reach a cylinder.
Mark