1965 Dodge Dart Speedometer

I have a 1965 Dodge Dart with the original speedometer. I am told this hooks to the transmission with a cable to work properly. It doesn't provide accurate information.

I would like to replace it with a gauge that has a speedometer and tachometer in one.

Anybody know of such a gauge that works with a cable?

Can I use an electronic one? How does it get converted?

Any help is appreciated.