information on tachometer wiring

George Jets said
Red wire power

Black wire ground

Green wire, signal from ignition coil

White wire, back light to work with dash lights circuit.

Is usually how most tachs are wired.

'66 (and '65) use a tach sending unit. They don't wire like a stand alone tach. I've probably got the diagram in the FSM, but I don't think it's scanned in.