Oil pressure gauge issue...

[yellow400ex05]

Alright so I've had my truck for almost 2 months, all the factory dash gauges worked great. The truck has a newer fresh rebuilt 350 in it, and runs valvoline VR1 20W50 oil in it which i know is quite thick. So when cold the truck runs at 75-80 lbs of pressure on the mechanical gauge i also have, until it heats up and will then run at around 60-65psi of pressure when cruising. so obviously the stock gauge only goes as high as 60psi of oil pressure so it was basically maxed out and then some when it was cold.
so 2 questions.
Could too much pressure break the stock electrical gauge? it seems to be stuck at the first line, it doesn't make a difference if the truck is running or not it does not move. all grounds are good and the connection at the sending unit is fine.

is this a bad sending unit or a faulty gauge?