What happened to the 300d that it is now a parts car? A word of caution, the 1985 300d has some electronic stuff for the tachometer and egr. You don't have to use this stuff for the engine to run but, if you want to use the 300d's instument cluster with a tach, you will have to transfer it over. But there are ways around that also, like using the 82-83 tach setup. Also, keep in mind that if it is a California model you will have the PITA trap oxider to deal with.
If you are going to do the swap, I too suggest that you replace the rear end with the 300d's. All in all I think this is also good to have this parts car so you can take a whole lot of pictures and just copy the set up over to the 240d.

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1983 123.133 California
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