I was doing a ZF-E4od swap and noticed a difference in Tcases between the 1992 E4OD 1356 and the 94 ZF 1356 Tcase. The one mated to the ZF has a PTO on pass side, double cardan front driveshaft and its front round transmission mating surface is larger than the Tcase off the auto.
I planned on reusing the Tcase from the 92 auto. It seemed to fit fine on the ZF ouput shaft and all six bolt holes aligned. However its mating surface diameter is smaller than the ZF adapter surface leaving about 0.5" step open to the cavity between the tcase and transmission. There is no damage to any of the parts involved.
Ive never seen 1356 Tcases differentiated between transmission types. I ended up resealing the TC that came with the ZF but thought I would share this observation

 

Run it you won’t have an issue.

 

By your description the zf mounted t-case is from a F350 and has Nothing to do with what trans it was bolt to

 

Yes the donor zf/t-case was from a f350. I didn’t realize there were different 1356’s depending on truck model.
I split the t-case and everything looked ok. Cleaned it up, welded a 1/4” bolt to the oil pump flange and resealed it. This swap was tough on me, getting older but it turned out fine and I’ve got my truck back. Can’t thank everyone enough on this site for help over the years