Hello. Hope someone can advise? Just about to put in a reconditioned engine into my 2001 4.0L p38. I was cleaning off the timing chain cover last night and noticed what looked like a slightly eroded hole in the oil filter housing. It looks as though the hole is designed to be there, but the edges looked quite thin, as if they had been eroded by oil flow. Should the hole be there? And should I be concerned about the eroded edges. Probably being paranoid, but any advice welcome!