I usually install the needles "live". Take the tach out of the dash pod, wire it up and start the car. Install the needle at your normal idle speed, and done. For a speedometer, I spin it up on an electric drill before I disassemble. If the drill drives it to 68 mph, that's where I'll set the needle when I reinstall.

I may have a tach needle from a 124 if you need it.