If you did find an analog tachometer driven through a cable. Where would you tap into the engine for the cable? And how would this be calibrated? I think an electronic tachometer with an analog dial would be much easier to locate and install. You can derive a signal from the primary of your ignition coil. I'd guess the pulses per second would be a factor of 2 and a time base conversion to get engine RPM. That would all be in the tachometer's internals. Just a thought. Good luck!

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