Speedometer Calibration

There is currently a thread about getting an electronic feed to talk with a mechanical speedometer and tachometer. In it there is a referance to a black box that makes this conversion for the speedometer. This black box evedently has dip switches for calibration.

Is there any such black box to get the electronic sender to display accurate MPH on the speedometer that is supposed to read in MPH?

The TH 400 in my Lincoln has the usual mechanical speedometer gear drive. This is changable for accuracy. Does the same geared set up feed the electronic sender?

I have made up a cheat sheet that matches RPM to posted limits but would rather have the speedo actually work accurately.

Greg

 

Thanks for the lead!
I know Ross Ortman who owns Dakota Digital and just sent him a request for further information.
I'll let everyone know how this turns out down the road.
Greg