This topic inspired me to finally post some info that Kinky6 and I have been collaborating on forever. This list may not be complete, but it's a start. It includes the NWC T5s from 1980's S10s and minivans. If looking at a T5 at a swap meet, these numbers can be a big help. If the seller knows the source of a particular T5, all the better. Hope this is of some help. Please remember that this page is a work in progress. Feedback, corrections and updates are welcome.
T5 Tech