Recommendations on how to fix Rust thru Hole From Head water jacket

Unknown

Guys I need some advice.

Finally found my water leak into cylinder 3 first, and the rest. I've got a rust thru hole about 2" forward of the front intake bolt. Sealing off the two water pipe fitting, with the head upside down and filling up the water jacket I get considerable water into the intake with filling from just right of the #3 valve guide (#1 facing right). I have not seen the hole yet, just out of view, and sun to bright to use the endoscope. I am curious as to the groups experience with this issue. I was wondering is a high temp gas tank sealer would seal the entire intake. I see no way to weld it..

Please brain storm on this please.

Thanks

Jack