Originally Posted by GagaPilot

If you check the master 737 mods thread here on FT you’ll find lots of info about the 73R and 73J variants that DL introduced over the last few years. In short, these birds were purchased because of DL’s knee-jerk reaction to Covid where they got rid of all their MD88-90 fleet and left them extremely short on aircraft, particularly those used on short haul routes ex-ATL. These non-standardized 737s operate a ton of short haul routes out of ATL and the occasional medium-haul route. They are slated to one day be configured to match the existing 739 config, but my prediction is DL will never do this as they have yet to make any attempts to do so, and friends of mine at DL in flight ops say it will likely never happen has well, or at least until the interiors absolutely dictate it.