hi guys...i,m new here. i just bought 1975 w115 300D. it is not run because the throw crank on the engine. i was wondering if you could give me advice on engine. should i swapped it with other engine or rebuilt the old one? (cost me real fortune)...if i wanna swap it what kind engine that could be use? and any idea who have or wanna sell it?

Where are you located?

I think what you are saying is that the crankshaft is broken. If so, you are in for spending some real big money to rebuild the engione. Better to find a secondhand engine at a junk yard. What ever caused the crank in your engine to break (old age, too many miles, hard running, no oil, etc.) will have had a bad effect on the entire engine. This means that if you do replace the crank you will also need to do a complete over haul of the engine. At this point it might be better to get a factory rebuilt engine. Either way you are looking at $4,000 plus. You might be able to find a useable junkyard engine for $500. Installation would be extra.