5.9 magnum.
I put a boat zinc plug in the block drain on the passenger side. there is one on the drivers side, but it is under the starter, so I am leaving that alone.

anyway I pulled the one on the passenger side up front to drain the block.
The zinc must have swelled, because it twisted off in the block. stuck in their pretty good. And it doesn't leak.
I can't get the original plug back in because of how far the zinc sticks out. I can't get the new plug back in either for some reason. I guess the zinc must have backed out a little.

since it doesn't leak I am tempted to leave it. see if it ever blows out.
or I read (assuming it really is zinc) I can dissolve it mixing salt and vinegar to make HCL and eat it out of the hole.
I think I can pour some in a flexible tube and then hold it against the hole in the block to get it to stay next to the hole, but the question is, is it worth that time. or is it being stuck enough and just let it go till it does blow out?

can I reach it through a freeze plug? maybe bend it out from the other side?