Fuel pressure lower after new fuel pump installed

[searcherrr]

New fuel pump, new fuel sending unit, new fuel pressure regulator, new fuel filter

After new OEM fuel pump installed and tank cleaned of severe filth the operating pressure at idle is 27psi and 26 psi under load of 2000 RPMs or higher. New fuel filter only ran for 1 or 2 tanks under filthy gas tank and pressure on key flick comes up to 38 psi before starting engine. Spec operating range is 30 - 45psi.

Since the operating pressure has gone down since new fuel pump has been installed and given all the new fuel system items what could this mean is wrong? Why am I not seeing the spec range? and... there are no leaks either.