Gauges not working properly

Just a guess, but if the guage has the white face overlay, and not the actual white face guages they may just be binding up, check and make sure the needle isn't coming into contact with the white face overlay if it is an overlay sometimes since the overlay is thicker it causes problems with the needles.

Setting dash gauge pointers after they have been removed to install white face gauges.

The middle mark on the dash voltmeter is 14 volts. Use a DVM across the battery with the engine idling and use that reading to help set the dash voltmeter needle accordingly.

The oil pressure sender is on the front of the engine near the oil filter. Make sure it is connected. It has a single wire that pushes down on the screw on top of the sender housing. The middle mark on the oil pressure gauge is 50 PSI. If you had a mechanical gauge tee'd into the pressure fitting for the dashboard gauge, you could use it to set the dashboard gauge.

The water temp sender is located in the driver side front of the intake manifold. Make sure it is connected. It has a single wire that pushes down on the screw on top of the sender housing. The middle mark on the dash gauge is supposed to be about 200 degrees. If you had access to a handheld infrared spot thermometer, you could use it to set the gauge. Open the radiator cap on a warm engine and aim the red beam at the coolant. Or if you have a cooking thermometer, you could open the radiator cap on a warm engine and immerse the thermometer in the coolant and use that reading to help set the gauge