It sure looks like oil to me most likely coming in from the bottom of the intake gaskets or the valve guides.
Stu if you lived closer we could have the next Moparts party engine rebuild cookout
Gus

7428617-savoyburnout.jpg (39 downloads)

64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60