High oil pressure reading

[C1ph3r]

hey guys. Finally brought my 70 C10 home yesterday from my dads.

So among the many small issues I need to address is the high oil pressure reading.

Stats: Original 350 small block. Was rebuilt about 9000 miles ago. But that was in the mid 90s. My grandfather didnt drive it much after the engine was rebuilt. My dad has been driving it off and on for the past year.
Mechanical pressure gauge.

So at idle the gauge is just at the half way mark. Once I start driving, it goes up almost all the way. Stops just before the 'H' line.

thanks for any help you can give.