I looked at the pictures here on the Nest of the Rollguy's Diesel Eagle, and the VM looks like its the worst possible candidate to try to shoehorn into our engine compartment. Those conversions were not done by AMC and I'm not impressed by them, even if I would trade my left foot to own one. I'm fond of reminding people that AMC chose the SD33 for their CJ tow pigs, some motorhomes, and a handful of full size Jeeps exported to Japan and Australia. I'm confident that AMC would have chosen the SD33 if they ever put a diesel into a production Eagle. It fits quite nicely in lieu of the 258.
They are incredibly robust motors. One infamous Scout motor has 700K miles on the original engine and still runs (barely). The engine comes with a sleeve at each cylinder that gets replaced during rebuild. Its hard to describe the driving experience, except that I loved it and instantly knew it was a worthwhile Eagle conversion.