'92 a518 vss to '97 OBD2, compatible?

Is your 92 harness a 3 pin plug at the trans? If so things are completely different. The later (6 or 8 pin connector I forget) trans is completely controlled by the PCM. "I think" my research has shown that you either need a later PCM and associated "stuff" or else a special manual valve body.

In other words you ain't gonna do it the way you are hoping. Go to the service manuals thread. There's a link there to a Russian site which you can dump into Google translate. You can get most any of the ATSG transmission manuals for free. Yes, they are pirate LOL

Free service manuals