it is not legal to do so in my state as of a lot of people used to roll the mileage way back and sell the vehicle's as a ''low mileage'' vehicle, but you can put a variable speed drill on the speedo cable and run it up or down to your correct mileage, as for the temp and oil pressure sender's/switches, I'm guessing you are trying to just swap the left side of the gauge cluster from the junkyard one into your's, if so, I don't believe you can, because IIRC they are internally sealed, and the circuitry is different on the back, if I am right, then you have two option's, 1: go with the tach and only have temp and fuel, or no tach and have oil, amps, temp, and fuel in the stock gauge cluster,