Increasing voltage

[Caddyroger]

I do not know if this belongs here or elsewhere. I installed a electronic oil pressure gauge today. I used the factory oil pressue signal wire because the way the Camaro it would be pain to install the after market sending. This is where it gets not a camaro.
The pressure is reading 105 at idle, 150 at about 1700 rpm.
I put a 460k resistor in the sender wire. It went to 150 at idle. This seems like it need more voltage to decrease pressure reading.
Now what need to know is there a electronic way to increase the voltage with the increase of oil pressure.
If there are a web site where I can research this let me know.