Is there a way to calibrate my factory oil pressure gauge?

[Harrison.]

I decided to go from dummy lights to gauges and bought used gauges at a swap meet. I know the engine makes good oil pressure as I had aftermarket gauges up until now but the factory oil gauge does not read correctly. I put a regulator on my air line and at 60psi it BARELY moves the gauge, unregulated at 90psi it only goes up to about 1/4 of the scale. When the truck is at idle it makes about 25psi and it doesn't even register on the gauge. Is there a way to adjust the gauge?

Thanks