left side oil

getting good oil pressure with a drill motor,but cant get oil to the left rockers...tried tdc and every 90 degrees...pulled the rockers and looked cant tell a thing..right side is pumping like crazy ..left side notch forward and down..right side notch rear and down..can I pump with the rocker arms off and not blow the lifters out so I can expose the oiling hole thru the head..and where does the crank have to be so the left upper will get oil..i did a search,and cant find it...thank you ..j