Oil pressure gauge

[investig8]

Hello again...
Today I am looking for help in determining if I need to replace my oil pressure gauge. The gauge is pegged out past 60 psi when the engine is running. I have put a manual gauge on it and consistently show 40 psi oil pressure. My question is, is it possible to connect the gauge backwards or is the gauge just bad?
Thanks,
Dennis

[Cal_Gary]

Could be a faulty gauge, the incorrect gauge (they also make a 120 PSI gauge), or the wrong sending unit (meaning mismatched to your gauge ie should be 60 PSI to 60PSI or 120PSI to 120PSI).
I'm no gauge expert-perhaps some others will weigh in!
Gary