So far I've found the 91-95 ones, still need the others.
If anybody knows what the 1990 version is, I'd love to know.
What I know: It appears they only offered one Master Tech class per year.
1989-LT5
1990-??
1991-Painting
1992-Auto trans
1993-Brakes/ABS
1994-Electrical systems
1995-Heating
1996-Steering