[D13]

The cast iron case versions are less common than aluminum, at least in our truck applications. I have never really looked to see if standard A833 Mopar cases are a direct swap. I have a 2wd and a 4wd, both are aluminum case. My 2wd is GM vin stamped and my 4wd case appears to have come from a Mopar, with GM input and oputput shafts.
The output shafts are different 2wd/4wd. There is one shaft that is different between aluminum and iron cases and the aluminum case version is no longer available new.
If you buy one be sure to get the shifter, it's a Hurst Competition Plus but the plates and links are unique to GM. Oh, and the van version is slightly different, mounts and shifter package and links.

Most applications are 6.2 diesels, 4.3 V-6, occasionally a 305. Dodge did some in 318 and 6 cylinder trucks. I'm not sure what would trigger an iron case versus aluminum, I'm thinking heavy 1/2 or light 3/4 4wd might have gotten cast.

Run a search, we had a pretty good thread about these a few years ago. Use A-833 as the key word.