So these instructions are assuming that you swapped your transmission that already has a mechanical speedo gear or have already swapped your electric speedo gear (picture of modified mechanical gear can be found here viewtopic.php?f=46&t=59373&start=37)
So the First step is obviously to acquire all the mechanical speedo parts needed which is the speedo cluster and speedo cable from an SOHC 4cyl MX-3. (possibly a 323 or escort?)
-After that would be to pull out the electronic speedometer.
-Now you want to route your speedometer cable, there's an existing hole in for firewall specifically for the cable.
I don't have a good picture but you get a pretty good idea of where it's located here. (I highlighted it with the dot)
- If you look at the back of the cluster's you'll notice that the ACC (ground?) is located in different spots so you'll need to swap over the wire on the plug.
If you look closely you'll notice a bar shaped flap at the top that you need to flap down to unlock the pins, and then after you just need a small screwdriver or pin to push out the pin.
- The mounting points for the cluster between the SOHC and DOHC (or 92-93 and 94+ dash) so you'll need to swap the brackets over but unfortunately the plastic..key? prevents it from just popping on so you'll need to cut off a little bit of it at the end.
This is how i cut it off, i just used a vice grip and it just kinda snapped off lol
And then the key will match up and you can just screw on the mounting brackets and just mount it in your dash =D
- There's a metal support bar that the cluster harness is attached to on the 94 that you you'll need to bend out of the way or cut off out as it's in the way of the speedo cable. (there's a screw at the top)
Make sure you don't route it the way i have pictured but instead route it the way i highlighted as it gives just the extra length needed for it to function properly.
To connect the cable you'll need to attach it to the cluster AND THEN tighten it to the tranny.
And that's pretty much how you do it. i don't think i missed anything since i took pictures of all the steps i thought were important, If you have questions just ask.
It's funny that it is digital yet takes a mechanical speedo cable! 
