I know you meant a OM617 but the statement "a 6bt is only 300lbs heavier than a w123" is closer to accurate.

What are you going to use for a transmission? You say a "five speed" but what kind of a five speed?

I have no idea what/how you could possibly configure a drive train. We used Dana 70 differentials in the fleet of 6BT engined trucks I maintained and they often couldn't take the strain. Now granted, the trucks were used and abused by the drivers but I don't see the W123's differential/rear suspension set up capable to handle the engine's power.

It's your time and money. I'll be watching this thread just to see the progress.

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