"part time" oiling gives a BIG squirt for a short time. Full time gives a smaller but continuous flow. Switching to "full time" is kind of a pain in the butt. You have to install the 4th cam bearing so the holes to the top end are blocked and then drill the hole from the main so it still feeds the cam bearing. Then drill through from the galleys into the top end feed passages and then plug the holes in the lifter valleys. Then tap the feed passages for set screws which you've drilled to approximately .062 to restrict flow. And then to top it all off ... a) worry that the plugs in the lifter valley might fall out or b) your small restrictor holes get plugged with some sort of debris and completely stop top end oiling.