This came from the Shelby Development center in Santa Fe Springs, CA.  I'm not sure exactly what years this will fit, and there's a chance this may have been removed from a prototype.  In any case, what you see is exactly what you will receive.  These airbox (aka factory air cleaner cases) are extremely difficult to come by these days, especially in such nice condition!!
 
Note that it has a built-in BOV.  Pretty cool!
 
Very nice piece here!!