There is quite a little swap information in the diesel section, but I don't recall a switch over like yours. But I think it could be done, if you know pretty well what you are doing and what you wish to accomplish. Most of the swaps are diesel to diesel, and some are quite complicated.
Usually on these more difficult swaps a number one need is to have access close by to both vehicles, the donor and the keeper. Parts are parts and there always seems to be a shortage somewhere. You are staying Mercedes so that is a plus. The 83 "S" class was available with the 617 turbo and there is a lot of info on that car in the diesel section. It might have a better rear end ratio for your engine. If you can locate a "S" with a diesel in a junk yard it might be very handy for some parts and if it isn't to picked apart it can be helpful for wiring and vacuum especially. So have at it. Get the camera out and take a lot of pictures so we can all see what you are doing. I am finishing putting a 617 Turbo into a former 240D with a 4 speed, and I think that would be easier then what you are doing. But there are plenty of parts around with members parting out car and plenty of good solid and good natured advice available when you need it.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!