I am the owner of a GT/CS, X-code engine, with a factory GT package, as verified by my Marti report. I know I've seen this discussion on this website before, and it's very confusing re: GT packages on our California Specials, but to state it one more time: the 390 2-barrel engine ('X' code) DID qualify for the GT package, and, I own such a car. Paul is also correct in that they did not all have the deluxe interior, although again, my car does. I have a real odd-ball among GT/CS's.