I was looking at my cannister-style oil filter the other day, trying to figure out how hard it'd be to go to spin on, when I noticed these bolt holes with nothing attached to them.

Can anyone identify? I've looked at various photos of engines, haven't seen this area shown exactly. They're to the right of the oil sending unit, on the right side, toward the front of the engine down low.

Any guesses?

 

I looked at my engine block from a 66, 4.2L. I did not have the upper bolt hole. The lower, closer to the sump is one of a line of casting plug bolts with copper washers. These usually just close drill passages that were used providing oil feed passages within the block during assembly. The upper could be for a sending unit, oil most likely.

Hope it helps.

 

Thanks so much! Very helpful. Will investigate how I can plug those this weekend. My sender is very much in place, so just want to disguise them a bit. I think my restorer had plugs in them when he painted the engine block, the removed them, 'expecting' them to be filled with something.