That’s going to be difficult to find out. I would imagine 1993 model year trucks were built well in 1994. However, the last one built “in 1993” would have been a just a few days before Christmas. Most American manufacturing plants, especially automotive plants shut down production for a 1-2 week period around Christmas and New Year holidays. This gives most employees holiday time off and maintenance crews get time to do in-depth maintenance, major repairs and improvement projects. The same thing often happens around 4th of July in the summer.