Electrical vs. Mechanical Gauges

Mechanical gauges typically have more sweep making them easier to read but the connections are harder to route.

Electrical gauges have less sweep but the sensor wiring is far easier to deal with.

I have an Auto-Meter Speedo and all I had to do was measure out a two mile route through the nieghborhood with my daily driver, hit the button on my speedo, take the exact same route (no burnouts lol) and hit the button again. Presto, calibrated! If I change tires or gearing I just need to repeat the process and no worries about changing out gears in the tailshaft.

Nice choice on the ES series. That's what'll be going in the Duster. I'm using the "Streetrod Designer" series in the Ramcharger.