My MGC came with a pretty extensive history file but there are several routine maintenance items that are difficult to determine when they were last accomplished.  One of these items is the spark plugs.  So, since they are readily available and cheap I decided to change them out.  Replacements are readily available from Champion (type N9YC) or NGK (type BP6ES).  I also purchased a video boroscope prior to starting this project to enable me to take  look at the inside of the engine to see if there was anything I needed to be concerned with.