1956 Chevy 3100 pickup with 235 engine:

Well, I managed to remove all the freeze plugs without much trouble. They didn't pivot like some said they would. Mine just dropped down inside so I used a magnet to bring it up where I could use vice grips to remove them. Now it's just a matter of doing a super cleanup of the surfaces.

What surprised me was that both of the large plugs in the back of the engine appear to be oil plugs versus water jacket plugs. One at the back of the cam bearing appeared oily and the large, nearly flat disc plug was coated with oil grit. Plus the opening had a large amount of caked oil sludge covering half the opening that I pulled out. Inside this one there was a large amount of sludge buildup that I removed as much as possible. I plan on pouring gasoline down inside it to loosen up more and then shoot air inside for cleaning.

My question is why freeze plugs for two areas that evidently are oil areas and not water jacket areas?