Just found out some info on the SAAC forum. There was no '68 Shelby with a 427 engine. There was in fact only one(1) 1967 Shelby that was documented as having a 427 engine. And I found an article in Mustang Monthly August 2001,Page 11, that says there was never a '68 Mustang produced from the factory with a 427 engine, and that Kevin Marti's database has confirmed this.