I recently was gifted the truck described in the subject. It has a persistent oil leak. The oil sending unit was giving a 100% reading, so I replaced this sensor. The valve cover gaskets had a slight leak, so I changed both. In both cases, the new installs are dry. At this point, I still have an oil leak that seems to come from either side of the oil pan. The bolts on the starter are soaked, and the oil cooler mount (not present) on the opposite side is also soaked. I suspected the leak was from a failing rear main seal, but the inside of the bell housing is bone dry along with the flywheel. Any recommendations on next steps?