As an update, I bought 10 fittings as an experiment and have sold the other 9 to people wanting to test this with me.
My theory: The oil is being slung up onto the vc from the cams and it runs down the side of the VC right into this hole:
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You can see that area appears washed clean from oil. The custom fittings actually protrude two inches into the hole so the oil will get caught on the threads and drip down instead of going into the hole.
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Here is the drawing for anyone who wants to copy it. I sent a request out to several random companies online and this one from England of all places was the smoothest to deal with so I proceeded to use them despite the distance. My contact was Andy AT customfittings.com and the description is:
1 – 7/8”-14 JIC x M18 x 1.5(Flat Faced)WITH A 2”LENGTH OF THREAD MALE/MALE
HEX ADAPTOR AND THE METRIC END WITH A 7/16”BORE
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Keep in mind, I had a larger than normal drill used for the M18 side, I choose 7/16 but after receiving it I can tell there is enough margin to do a 31/64" straight through.
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The shoulder is also round just like the head, it is a perfect fit:
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I'll hopefully get a chance to test it in the coming weeks.