What the deal on them was, Mitsu didn't make a 4wd truck at the time, or else there was something preventing them from sending them here. So, Dodge got the idea of converting 2wd Mitsus to 4wd, and had farmed out the work to a couple or three shops, one in CA and one in UT (I think). The period of time that they did these conversions would, I think, correspond to a time previous to 1982.

I just don't know anything about the axles used for the conversion...just that they were Jeep-ish, prolly off a Wagoneer (for the bolt pattern, if nothing else).

If that one model number of hub IS for those particular trucks, they wouldn't be compatible in any way with the newer trucks. As far as telling the difference in a boneyard, it'd be a matter of looking at the front axle...if it's solid, don't use the hubs. They may well not even mount the same way (six large bolts). The hubs most likely wouldn't be Aisin, either...prolly Warn or something.

Dan has at least one of these trucks, and would be the one to confirm or deny my hypothesis.

The D50/Arrow pickup was introduced to the US market in 1978. It was 2 wheel drive only.Dodge did convert about 4000 a year into 4 wheel drive.
In 1980 a 4wheel drive version was made by Mitsubishi. These were still sold under the dodge moniker. Mitsubishi did not start selling cars in the US under their own brand name until 1982.
I am not sure what the differance in hubs are with the pre 82 versus the latter years.
And yes my 79 Arrow has Warn hubs on the Dana 30 axle.