GM/Chevrolet did not call them Advanced-Design; GM/Chevrolet called them Advance-Design.
Did you read the GM announcement I linked-to above? That term was regularly used.
Look also at my name at the top of this post. Click on the image to the left of it. It is a GM illustration.
Go to my website (the link is below). You will see several other GM references to their Advance-Design trucks.
Their next series of trucks was called Task Force.
Prior to Advance-Design, GM did not officially have a name for a truck series.
GMC also started using a series name in 1947, New Design (no hyphen) GMC trucks, followed by Blue Chip GMC trucks near the middle of 1955.
