The R prefix means it’s a Reman trans.

Besides that, the only internal differences are for shift quality - number of frictions is the same, band material, etc.
Front clutch spring rate differs, a few minor details inside. The case may differ based on if it fits the Durango or the Ram.

If it looks the same on the outside use it.

By coincidence, I saw this after posting I have Cummins coolers for sale.