oil pressure gauge question

In case this info helps, I had all my gauges rebuilt and the electronic limiter installed plus, I bought a new sending unit and cleaned my bulkhead connectors. My oil pressure gauge only goes up to the second line when cold and down a bit once warm on 3 different engines a rebuilt Slant 6, a tired 5.9 Magnum and a new 408 Stoker Magnum. The Temp gauge has always been just below half way once warm. Fuel gauge is pretty darn accurate and has a fresh 1/2" sending unit and tank.

One of these days I'll have time to put in my Vintage Air Gen V, my console with an aftermarket shifter in place of the stock shifter and an aftermarket oil, temp and volt gauge. Yes, I did the Amp gauge bypass. These three items end up in pretty close proximity to each other under the dash, which is why the Aftermarket gauges are not in yet.

My Factory Mopar OBD II ECU does monitor both oil pressure and water temperature to some degree too, but I do want to augment engine vitals monitoring with some analog gauges as soon as I have some spare time.