5.3L & 4L60E - Speedo Questions

[smokinstang70]

As the title states, I'm doing a 2006 gen III & 4L60E swap on my 71 c10. I have come to the point where i have to decide what to do about the speedometer situation. I would REALLY like to keep the factory gauges!! I know there is a mechanical tailshaft kit (approx $500) and I know there is an electrical box you can buy to convert mechanical speedometer into electrical signals but I have heard that it doesn't work well.

Does anyone know if you can buy an original guage that is controlled electically? Is there a kit? Can you buy one?

Any other ideas? Any and all suggestion / ideas are welcome.

Thanks