Its not that you can not, but you shouldnt. Pressurized oil to the roller bearing is a GOOD thing and it only needs a small oil supply hole in the bushing to get enough oil to the roller, .060" or so. Al lot of roller lifter failures have been do to the needles failing under extreme pressure and not enough oil to keep them clean, lubed and cool. Relying on only oil splash and run down from the top end, you take your chances.