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.
What's the scoop? Does it work but it's just inaccurate
The op hasn't been online here since he asked the question. I'm outta here!