And I qoute, from the "How to Hot Rod Small Block Mopar Engines" by Larry Shepard: "The #2 and #4 journals on the cam have a hole drilled through them. The oil pressure comes from the top of the #2 and #4 main bearing straight up to the cam bearing. The next step is to go to the valvetrain in the cylinder head. This passage is in the top part of the cam journal. Therefore , the pressure has to come in the bottom, around the sides of the cam and out the top (actually slightly to one side).