My understanding is that the M gets its oil supply through the shaft nose drilling, vs the MW that has an external oil line.5) Oil hose connection. Now there is the locking in the place, which locks the pump for timing. The drilling where the locking pin goes is seen in the pic3. When the pump is installed and the timing is right, remove the locking and install oil hose connection as seen in the picture.
I have had my M installed for 28k miles with no problems. I use the old MW's supply point for an external bypass oil filter.
The question is how necessary is the external oil line? It would only be flowing into the governor housing sump from the point they use. Something to do with the extra load of the 7mm elements?