Hey guys,
I recently purchased a 2000 323CI, had a blown headgasket and I found a low mileage 2002 325i M54 engine. I have been picking away at it for a while now, I have run into an issue with the intake manifold. I noticed that there is a slight difference between the M52 and M54 with respect to the adjusting unit (?)

the piece that has the rotating flap that isn't the throttle body. It has a different bolt pattern and harness connector. I thought I took pictures but I can not find them. I will update ASAP.
My ultimate question is - is there any advantage/disadvantage to putting the M52 intake on the M54 engine.
Also, I have oil in my engine ECU that I assume came from the oil level sensor.. Is this common?
And lastly - not really, I have more stupid questions to come in the future - has anyone replaced their exhaust mani studs with bolts? I was able to get my hands on some M7 bolts at work and we have spacers that just matched up perfectly (see pictures). I am hoping it is not a complete disaster. My logic is that heaven forbid I need to change my cats I will not be fighting for clearance. If no one has attempted this, I will update you once I get everything reassembled!
Thanks in advance.