* 1993-2004 SVT Cobra: Typically had a 4.6L V8.
* 2003-2004 SVT Cobra Terminator: Also a 4.6L V8, but supercharged.
* 2007-2009 Shelby GT500 (often considered a modern Cobra): Featured a 5.4L supercharged V8.
* 2013-2014 Shelby GT500: Had a 5.8L supercharged V8.
You need to specify the *year* of the Mustang Cobra to get a precise engine size.