Originally Posted by phunk

In the Z you need to remove the engine to remove the upper oil pan. This would get you access to the rod bearing. If you needed to do the main bearings too the bedplate will have to come off and thats essentially a full tear down except you can leave the heads on.

I suppose you could also drop the crossmember to get the upper pan off but that is a nightmare. I did that with my DE once to change the rear seal housing and it was torture being under there with the engine dripping oil on me the entire time.