All the VSS or GPS converters I've seen, still have a cable connection from the unit to the speedo. Sorta defeats the purpose, and there's something else you've gotta fit under the dash or in the engine bay. I think they were a similar price as an electric speedo.
A friend was working on a stepper motor that screwed to the speedo. He never got it worked out.

 

I did see something called Cable X that is similar to the style you mentioned. It is far too expensive for what it does and like you said it still requires and actual cable which defeats the purpose I'm looking to accomplish. I'm not really looking for anything like that. I think it is more more late model transmission swaps just to make everything work.

Did your friend just give up on it or have a lot of trouble and decided it wasn't worth it?

I thought someone offered a kit for this several years ago.

 

I also thought it existed. Apparently we were wrong.
I think he decided it wasn't doable.

 

Several companies make a gps drive to run cable speedometers. Speedhut makes one called Speedbox I think. Still a cable but,...

 

Classicinstruments.com sells a new cluster with a VSS speedo, and may also sell the speedo separately.

Classic Instruments Store / 1965-66 Mustang Package

shop.classicinstruments.com

 

I really want to get the Hye Po instrument cluster bezel with a nice set of full gauges, but that is a project for another day.

I'm interested in eliminating the speedometer cable and using a VSS on my T5 with an electronic driver on the back of the factory Falcon style speedometer. I remember seeing a kit a few years back but now I don't seem to be able to find it. Does anyone know who the manufacturer was or where to find it? If not, has anyone done this mod with a Fox Body VSS and some sort of electronic driver / stepper motor that mounts to the back of the speedo?

I'm no longer interested in wrestling with the speedo cable when pulling the cluster.

SpeedBox™ Mechanical Cable Drive Converter

 

SpeedBox™ Mechanical Cable Drive Converter

I wonder if you could get a short adapter (like a ratio adapter ) that would go on the speedo and attached to that box,build a bracket that goes on the back of the cluster to hold it,so it goes in and out with the cluster ? Obviously with a 1 to 1 ratio.............https://www.ebay.com/itm/124158136974
or even a 90 degree style..........https://www.ebay.com/itm/113647942286

 

Seems like it would be easier to get the 5 piece GT gauge panel and cut a hole in the backing plate (whatever that's called) to mount a GPS speedo.

You could mount the GPS speedo from the front and use the other stock gauges.

 

Those are all great ideas. If I do anything that has a significant dollar amount attached to it, I will just get a 6 gauge cluster bezel and a full set of aftermarket gauges. I was thinking there might be a way to just modify or add on to what I have for not a great deal of money.

 

on a more selfish-bad-influencey note, lmk how that hye-po cluster is as I've been looking at it for awhile if you end up leaning that way