They fit the 616/617 4/5 cyl. Mercedes diesel engines. The 2.4 616 is perfect for an 88" and will work in a 109 but may be a bit underpowered at around 70hp. The 3.0 617 is a bit big but it's been done before, but not by myself. That may be my next project. Anyway, both engines have the same rear pattern and this adaptor will work equally well with either.
The adapter with all the studs and bolts and a pilot bushing is $600 US plus shipping.
If you're interested, drop me an email.
jim
pbs@mohawk.net
Edit: Here's what it looks like done.
