Not easy or cheap to do no matter what direction you go. All diesels have pros and cons and all need various levels of downstream mods to make work. One other to consider just to help is the cummins B3.3t. Its used in a BUNCH of stuff and can be found used or purchased brand new. If your gonna do the swap and go through all the trouble and expense.. may as well start with a new motor?

Thanks salad. That was very informative. Do you think I should mess with all the other systems like fuel lines and exhaust before putting the engine in or after

Er, how so? You're converting to a different fuel type and the exhaust will likely move. It kind of goes hand in hand with the actual engine swap if you want it to run lol

Oh and my comment about the VM Motori, I didn't really need your name before. Are you in Germany (or really I suppose anywhere in Europe)? I guess the VM Motori engine would be a bit more common, though still suck, the Cummins be a tad hard to find lol. Mercedes should be aplenty. They came in the 70s and maybe 80s 300D sedans I think

I wish I was in deutschland but sadly, no. Im down in new orleans. Where hot wheather is plentyful (to damn plentyful)