Drilling the overlapping holes to almost through.

how did you connect the filter to the oil passage to the engine ?

did you put another plate over this to prevent dirty oil from falling in and going straight to engine ?

This pic is showing how I overlapped holes from one end of the slot to the other. I then cut away as much of the edges between the holes. One end gets drilled and tapped for an oil filter adapter. The other end feeds oil to the oil pump.
I sealed this slot with a section of thin steel sheet metal. I "glued" it in place with JB Weld.
Leo