20yeartec

Im working on a 99 f250 4.6 romeo engine.First started with noise on the right of engine sounded like the chain flopping and poss some lifter noise only on the right side.So i did a oil presh test and found 40 psi so i tore down the front of the engine and found the right chain flopping and 5 of the lifters bleed down. the right side valve cover showed little sighn's of oil.On the left side seemed to have oil,so i took a starter swith and turned the engine over only to find oil pumping on the left side but no oil on the right.So i went ahead and replaced all the guides,tentioners and chaines thinking mabe the left side tentioner was bleeding by.Nogo still only got oil on the left side of the engine and still maintaining 40 psi of oil presh.Oh and the engine inside is spotless no build up at all(vary clean).Is there anyone that can tell me the paths the oil takes to get to the top or possibly where it is going or stoped at?????91000 miles