Question on Van Nuys LS6 with NA9

[SS427]

Does anyone have an original Van Nuys 70 LS6 NA9 equipped Chevelle with the original radiator top plate or a copy of the build sheet (VIN is not important to me) as I am trying to determine what tune up decal code was correct on a January Van Nuys LS6 with NA9. Every VN build sheet I have shows a DT code in that time span with AZ coming much later but this car is very original and has an AZ decal. Coincidently, all of the build sheets I have are for non NA9 cars so I am wondering if that is what makes the difference. Any help is much appreciated.