I did this same thing the passed week. I always reset my odometer at every fill up to check my MPG and incase my fuel gauge F's up, I know that around 280-300 miles fuel up. but as for your gauges, I would fill my truck, bring it home wait for the next cold morning, turn the key on, put in your oil at zero cause engine isn't running, fuel gauge at full, temp at zero, as far as volts, use a multimeter when your trucks on and put it where its close? I had a older 5.0 Stang a while back where I did a gauge color thing, when you put the gauge needles back in dont push them in too hard, or they wont be able to move.