Blaine told me there used to be some companies that convert Datsun 620 trucks to 4WD using jeep parts. He provided a few examples:

And here’s another. This one is for sale:

http://www.shoppok.com/corvallis/a,45,63757,1975-Datsun-620-4×4-Conversion—-4200–Lebanon-.htm

A comment on cargurus also mentions the use of jeep parts with Datsuns:

“There were machine shops who did the conversions that individual dealer had contracts with .Datsun were built by spencer low, southbay, quadco,northwest atv. They used early jeep components dana axles and the semi tough dana 300 tease. Early models used Jeep rear end also to keep 5 on 5 1/2 matching wheels but them the datsun rears were retained with a machined front hubs to run the standard datsun 6 lug wheel.. most conversion company’s added a tag under the vin tag on the back of the driver door sil ,quadco had stamped shift knobs I’ve owned 5 datsuns 73-79 converted to 4×4 a 76 courier sasquatch 4×4 conversion.”