Why 10.7 volt input at ‘71 Duster instrument panel?

Thanks Red. The reason the Sunpro is specified is that the original thread details "fit," the gauge is fairly compact, and also, that it has an internal pot so you can calibrate it. Many of us adjust it so that 14V is right at the center on the old ammeter scale, IE you are driving and normal, charged, alternator running correct voltage, the need is then centered, just like an ammeter would be