Easiest way to add a tach to your Ranger would be to get an instrument cluster from a junkyard Ranger of the same vintage with the full instrumentation. Should be just plug and play. '93s and '94s seem to be somewhat proprietary. Clusters from other years won't quite match up in all functions. I've got one from a '92 I believe and I don't have the seat belt light or parking brake indicator. Some Explorer clusters will also work but will have the wrong redline marked. Also some of the Explorer clusters are marked for use only on the V8. Another source would be Ebay. I think my cluster was about $45.