From what I can make out from other on-line groups, the Linden oil trains are up to perhaps a few times per week and will ramp up to daily as more tank cars are built.
66Z carries the inbound loads, 67Z the outbound empties, roughly 100 cars in each inbound train.
Since the loads are coming in via the NS Lehigh line and then probably the Port Reading line, there is a chance that between Manville and Port Reading Junction, a lucky photographer will catch a loaded NS oil train moving east and a loaded CSX oil train moving west passing each other -- CSX runs at least one if not more oil trains down the River line from Selkirk to NJ and then west on the Conrail Lehigh line and then the CSX West Trenton line to Philadelphia daily. (Actually, I am not sure if the CSX trains run west on the Lehigh line all the way from Oak Island to Manville or if they take the chemical coast/Port Reading line route - the latter would give even more passing opportunities.)
JS