I have a restored 1969 Z/28 built in Van Nuys. This vehicle does not have it's original engine or trans. but they are date correct with lots of reproduction parts. Since LA didn't use X-codes on the cowl tag is there any way determine if this vehicle was actually born as a Z/28? is there any uniqueness to a Z/28 with it's body beyond the obvious i.e. front disc brakes, exhaust hanger pad, etc?