dwferg,
I recall that MB says the 300SD engines are just over 400* when new, and at 285* or less, with no more than 15* between cylinders, MB recommends an overhaul, so the further up into the 300*'s you get, the better for you from the git-go, and the longer the engine should last. I have personally seen those engines with numbers in the 200's in all cylinders running every day for tens of thousands of miles. It's a diesel, remember, so it'll probably run even with numbers in the 100's. Not with any zip, but probably still get up to 75 mph on the highway. There's a theory about those engines that says if you can't afford to rebuild your working engine, just change the oil regularly and run it till it can't do highway speeds safely, or, local street speeds. Depends on the type of driving you expect to do, and how much of a 'lack of acceleration'' safety issue you are willing to live with. Higher compression #'s = better acceleration, longer-lasting engine, but usually more $$ up front. If you could get 350* plus from a salvage engine, you'd be getting a steal. Good Luck!

SteveKaa
______________________________________________________________
1982 300SD 338k miles