Hello, I'm new to the forum, and the M-B diesel world as well. I have a '67 200D that is in need of an engine upgrade/overhaul. What I have is two clapped out, but complete OM621 engines. They were torn down when I got them, with reports of smoking badly. Upon inspection of the cyl-heads the cam/rockers/bearings look pretty beat up, and nothing measures up to spec according to the factory workshop manual that I got. I havent torn down the bottom ends yet, but the piston tops look hurtin', and the bores look a little oversized as well. Is there any common failures on these engines that I should know about? If rebuilding is not economical, what engines will bolt in with minimal or no modifications. I can handle the work of retrofitting an engine, but would rather keep it stock, or stock looking as possible. I did a search, but didn't find anything out there. If anyone knows any good sites with engine data and such, please let me know. I really want to drive this thing.

Thanks
Erik