High oil pressure reading

[85k25]

I have an 83 3/4 ton with a 350.  The truck has factory guages and the oil pressure guage is pegged to the right with the engine running.  With the key on, engine not running the guage goes to zero as it should.  I have a high volume oil pump in the motor but i never had any readings over 55psi with the mechanical guage i had in before.  Could this just be a bad sending unit?

[slamd83c10]

thats is correct, bad sending unit, or wired wrong, could be a bad ground somewhere too but i highly doubt it, sounds to me just like a bad sending unit, been there done that so i switched to mechanical gauge...