I have swapped out a complete interior out of a '93 into my '85. I would like to update the gauge pod as well. I have figured out all the wiring on the '93 gauge pod. Everything should be simple with the exception of the speedometer. The '85 has a mechanical speedo cable. Install a speedo generator on the cable end in the dash? or a sending unit on the tailshaft wired directly to the speedo head?

Has anybody done anything similar?