Speedometer Question

[Heretic]

I've been lurking lately and reading about the speedo's in these cars.

Now I am curious: Is there a way to make a 90-91 Electric speedometer work in a 79-89 car? Has anyone tried? I know at minimum a VSS signal would be required, but is that all they take or is there more to it? Is the motor part of the speedo housing? Can the motor be integrated on a 79-89 speedo?

Please pardon my ignorance but I have never seen the 90-91 style up close and in person. If there's a way to eliminate that damn cable I would love it.

[gadget73]

If it would physically fit, then it should just be a matter of wiring it up. I imagine the plugs and wiring is all different, but thats not impossible to overcome. You should have a VSS already for cruise control purposes. Should just be a matter of tapping the wiring and feeding it the speed.

I doubt you could easily add the electric movement to an older cluster. I imagine there are enough differences to make it impractical if not impossible, though I have never taken a close look at the later style cluster. I've had the cable drive ones apart several times though.

[Heretic]

This is on my '85 which is now home to a 4r70w. I thought of this today as a way for me to cheat having to buy a speedo cable that fits a vss. The current cable is one that gets installed directly into the trans and I they are different from my understanding. I am going to need a vss for the Stang computer though so killing multiple birds with one stone is always a good thing.