I have a '91 350SD with replaced rods and a valve job. I have the old rods as proof! I have 190k and love the car. However, if I hit your $, I would probably find a clean '86 or '87 SDL. Search for this model, they did have some problems (lesser cost, however).

How did you discover your problem? How long have you owned the car? Usually, I heard that this engine failed between 50k-100k miles sometimes over. Never heard of 215k miles though...