DT466E was introduced in 1994 and ran through 2004. I believe they dropped the "E" designation for 05-07 with a different system (electro hydraulic)
DT 466E (7.6L): Introduced in 1994, added electronic control to previous, non-electronic DT 466, superseded by model year 2005-and-later DT 466 with variable geometry turbocharger (see below). Also changed over from mechanical fuel injection to electro-hydraulic unit injection (HEUI).
https://en.wikipedia.org/wiki/Navistar_DT_engine