Do a search for "Hercules Diesel" and "M-715" or "M-37." The DOD did some conversions (using the above mentioned motor w/ related accessories as a QEC) way back when. Some surplus company has a few kits on hand. All Jeeps shared the same class of motor (s) over the years so fitting should not be a problem.
Also, look for "CJ-10," "Jeep tug," "USAF aircraft tug," or some variation of that, because there is such a thing as 2WD Nissan SD-33 diesel 6 cyl. powered tugs cruising around Air Force bases (I saw one today). Essentially a CJ frame with a pickup-type body (complete with removable top) and a short service bed. Have a look at "eBay" or "Government Liquidators" (contractors to dispose of surplus equipment). BTW, it's the same diesel -with turbo- that's in the diesel powered International Scouts: 1977 thru 1980.