I repeat that the original style plugs are excellent if properly installed. I personally use the brass versions so that corrosion is less likely an issue. I keep things a long, long time. Other types of plugs might be a bit more forgiving of installation and maintenance errors and carrying an expandable rubber plug as a spare is not a bad idea. Another thing to remember is that our old cars were not designed to have pressure caps installed to create the pressure at which our modern cars are typically operating. If you use an excessively high pressure cap you are at greater risk.
---------Marshall Goodknight