Stock oil pressure usually sits around 20psi at idle, going up to 60psi during operation. Increasing the oil pressure is good for high-rpm reliability, as it keeps the bearing surfaces lubricated better. It places a small drag on the motor, probably a fraction of a horsepower, more than worth it for engine longevity.
To increase the oil pressure, remove the split pin on the oil pump relief and insert a shim (like a washer) into the sprung cup that comes out, usually something of thickness ~3mm will do it. This also gets your oil pressure up more quickly at idle, important because most of the wear on an engine happens when it's warming up.
its a sump off job, do it if you have to do a sump gasket or the engine out.