Saw a discussion on another forum that stated that there were never any 427 engines installed from the factory in any Mustang or Shelby.When I stated that there were 3 427 Shelbys built in 1967 and documented. I was told that didn't count because they had all left the FACTORY with 428 engines, and the 427 was installed by SA. I have always thought that SA was a manufacturer...would like some input on this subject.