The only way to really do this and get through emissions is to swap into a truck that is older than the engine, and make the EGR look functional. My swap into the Courier is actually legal since the truck is an 81 and the engine is an 82. Since I am also swapping in a Dana 44 front axle, and running at least 31s, I'm expecting low 20s, with a high of 25. Anything more is just a bonus.
If you are in a non-emissions county, then the post-86 Mazda will fit this engine pretty well. Here's a video of one in a B2600i Cab Plus:
http://www.youtube.com/watch?v=e2fWrqShmys
He has a bunch of other videos of that project, and it's a pretty clean install.
The 85-94 Toyota pickups fit this engine pretty well, as it's about the same length as the 22R/RE. There are a few guys who have done this swap on the 4BTswaps.com site.
This guy is one of the ones that inspired me to go the direction I am:
http://www.4btswaps.com/forum/showthread.php?8362-89-Toyota-4runner-OM617.952-Benz-Swap
A 4Runner on 38s that gets 17mpg, just unreal.
If you want an adapter plate for just about any bellhousing, let me know. I haven't installed my engine yet so I can make an adapter as long as I can find a transmission to adapt.