As dhill-cb7 found out, the 1998-2005 Chevrolet Blazer, GMC Jimmy, 1999-2000 GMC Envoy, and the 1998-2001 Oldsmobile Bravada use the chassis code GMT330. We aren't fully sure when it was introduced for the 1983-88 generation though as only Wikipedia states the name originated during the late 1980s.