95 4wd 3.0L low oil pressure on remanufactured engine
 

I just put a remanufactured 3vze in my 95 4 runner. Oil pressure is too low at operating temperature. Only 1 pound at idle and 11 lbs at 2500 rpm. Spec is >4 idle at temp and 35-70 @2500 rpm at temp. Significant oil is noticeable under the valve cover when viewing thru the oil cap opening at temp.
When cold it is 50 pounds. How can I determine if the problem is the oil pump or blocked oil return ports or bad oil pick up tube or blocked screen??????