The first 4 digits indicate transmission type, and the last 7 digits indicate serial number, on the tag (1).
The Hydra-Matic 4T40-E transmission has a metal identification nameplate (1) attached to the case exterior.
Items listed on the ID nameplate:
Additional transmission identification information is provided on the Service Parts Identification label. This label shows the Regular Production Options (RPO) as well as the standard and mandatory options. This label is affixed to the inside of each vehicle at the assembly plant.