Hey again!
The
oil pressure should be between 32-35 psi at idle and I have been told to use single viscosity
oil - I use 40 wt in my car. I have 32 psi at idle and 93 psi at 6200.
Oil pressure is controlled or set with the regulator/spring in the back of the block/oil galley - sorry I don't know the exact name but that is what is used to set the pressure throughout the engine. Best wishes!