What are the Differences?

What are the differences between DIS Modules 89-90 and the 91-95( not sure), I know they got different part numbers but I believe I have an 89 DIS on my car and it runs fine, mines a 92... so I've read and people say it won't work but obviously it does.

So...?

Take a look at this FAQ:

http://66.36.160.39/forums/showthread.php?s=&threadid=18403

The 89-93 are essentially the same, but the 94-95 will not interchange with the early years, since the electronic ignition was upgraded in 94. The 94-95 is physically different and mounts in a different location in the car.