oil pressure gauge question

You can get an idea what the gauge might be doing by both checking the others and by subbing resistors at the sender wire. It's possible a bad terminal in the bulkhead connector. Be sure you are asking for the correct sender application. they are not "universal."

Resistor values / vs gauge reading. Fuel, temp, oil, all samo If all three are off, could be bad gauges, bad connections, or more likely the instrument limiter. Yours with a Rally dash is in the fuel gauge. INSIDE

L = 73.7 Ohms (empty)
M = 23.0 Ohms (1/2)
H = 10.2 Ohms (full)