3L 1989 water leak

This is my friends boat that I am helping him fix. He has the money, I have the tools and time.
We noticed a leak under the exhaust manifold and assumed to be a cracked manifold, gasket or block. When I pulled the manifold I could not find any traces of cracking or leakage on the gasket surface. However there is a lot of rust stains above and below the front port freeze plug.
Question. Could rust stains be an inch above that plug or maybe am I missing a gasket leak. We could not see the source of the leak while running, which was a pretty good stream, and now I have the manifold off. Should I go ahead and replace the plug.
He drains the water every season and is a fresh water boat.

Thanks for your thoughts

Re: 3L 1989 water leak

Post a picture so we are sure of what you are talking about.

How to Post Pictures - The Basics?/ 468676

Re: 3L 1989 water leak

I must be doing something wrong in posting a pic. It says "file too large" but I'm only trying to post one pic.

Re: 3L 1989 water leak

there is no water transfer between the block and manifold gasket.why not just fill the block with water. I`m sure it will show if it`s that big of a crack.

Re: 3L 1989 water leak

mygrady said:

I must be doing something wrong in posting a pic. It says "file too large" but I'm only trying to post one pic.

Click to expand...

Don't try to post it full size, just use the first part of the link on how to post pics.

Re: 3L 1989 water leak

He has a cracked block. There is a crack running about 6 inches long from about 2 inches over the top of the front port freeze plug back almost the center of the block. Do you think he can find a short block pretty easy or what other options would he have.
Thanks to all.

Re: 3L 1989 water leak

mygrady said:

He has a cracked block. There is a crack running about 6 inches long from about 2 inches over the top of the front port freeze plug back almost the center of the block. Do you think he can find a short block pretty easy or what other options would he have.
Thanks to all.

Click to expand...

Ayuh,.... either a short block, or Long block,.... head's probably cracked too....