Where is the oil pressure relief valve located on the Ford 300 L6 engine?

I have a 1994 Ford F150 pickup regualr cab 2WD. I need to know where the oil pressure relief valve is on the straight six.Where is the oil pressure relief valve located on the Ford 300 L6 engine?should be in the base where the filter screws on to the engine.Where is the oil pressure relief valve located on the Ford 300 L6 engine?There shouldn't be one. It works on a PCV system. If you are haveing problems with oil pressure building up, the system is stopped up, probably the PCV valve itself. Look in the valve cover for a valve about the size of your car cigarette lighter. Pull it out and crank the engine. Feel the bottom of it and see if you can feel vaccum being pulled through it. If you can't, replace it.