Thanks for the effort, I really appreciate it. I thought I was using RealOEM incorrectly…if that’s possible. I’ll keep you posted on what I find.

I was working on the motor for a couple hours this am and took the opportunity to measure the bolts...the knock sensor bolts were a perfect fit, so the flange takes an M8 and the hole in the block is 25 MM deep. I'll measure the flange depth when it comes in and buy an appropriate length. I suspect it will end up being an M8x25, or maybe even a 30 depending on the flange and washer depth.

Update
 

I wonder if the left engine mount bolts up to, or somehow involves the oil flange in question? I can’t find anything about the left side engine mount strut in RealOEM, only the right side which bolts through a mounting bracket for the AC it looks like? This leads me back to the bolts, which may be depicted on the page for the right side engine suspension/ mounting. Wherever that is.

https://www.realoem.com/bmw/enUS/sho...diagId=22_0070

The mounts can’t be the same for each side, right?

Update...
I measured the bolt hole depth on the flange in question (pic attached) and came up with 12mm. The holes in the block are 25mm deep so I ordered M8x30 zinc (chromium free) bolts to hang it with. Hopefully these will do the trick.

This is a strange piece to begin with. The M62 in the 540 doesn't use it as the oil lines to/from the filter housing stab directly into the block. Wonder why they changed the design.

Final answer to the bolt question
 

M8x30s did the trick. Flange took two o-rings, which popped in with a little assembly lube, and 25ish NM of torque.

I could find zero info on TIS or elsewhere on this flange, so I picked 25 because it’s easy to read on my super old wrench I’ve been using for low torque values (I have a digital wrench that goes up to 200) and it seems that most m8 bolts that attach stuff to M and N62 motors are at or around 22 NM. A drop of blue thread locker should deter any thoughts of loosening up.