Only on the SPID, as far as I know (ie, it's not etched or stamped anywhere else on the truck. The only thing would be if one of the line workers had written on the firewall with his crayon, to indicate to fellow workers what was coming).
Do you have the build information for your truck? If not, I would encourage you to check with the GM Heritage Center archive and see if you can get the invoice for your actual vehicle.
It's $50 or so, but well spent in this case I would think.
http://www.gmmediaarchive.com/
K