Here you can see some of the vertical scars
And I finally get to grab a good pic of the modified oil pan. Looks like it adds about a quart of capacity. Was done by the P.O.
309ci inline 6, 9.75:1 CR, Big Valves, ROLLER ROCKERS, Clifford intake and headers, Schneider 140H cam, DUI HEI ignition, 450 QFT 4bbl carb, Saginaw swap, FlowKooler water pump, Steel timing gears, 2.5in y-pipe into a single 3in cat and borla muffler.