and i am trying to make a list of them. 🤣
some statements are my guessing so you are welcome to comment if you feel it wrong.

1. 24361, simply marked "dx2-66" without suffix or voltage info. oldest standard 5volt model, revision is usually D or E0, mostly made in 1994. this model also marked as 486dx-33/40, dx2-50 and even dx2-80(must be as hot as cyrix486dx2-80 which emits 8watt).

2. 25220, marked "dx2-66v8t/nv8t" without voltage info. all models from this on were called "enhanced 486" as they incorporated enhanced power management features. still 5volt model, mostly made in late 1994 or early 1995, supposed to be made of same old process as 24361. also marked as: dx2-50.

3. 25220, marked "dx2-66v8t/nv8t", but with "3volt". first 3.3v model, but supposed to be still based on same old process, as the backplate is same size as 24361. also marked as: dx2-80nv8t. never seen any dx4-100nv8t with this model number so i guess it can't clock so high.

4. 25253, marked "dx2-66v8t/nv8t". made in 1995, believed to be a newer process(probably 50mm) as the backplate is noticeably smaller, and i see this as the "mainstream" 3.3v model. also marked as: dx2-80nv8t, dx4-100/120nv8t.

5. 25398, marked "dx2-66sv8b". updated with writeback cache, made in mid 1995 and on. also marked as: dx2-80sv8b, dx4-100/120sv8b.

6. 25498, marked "dx2-66sv8b" or "de2-66v8tgc". the latter indicated an embedded model but i have no idea how it differs from desktop ones, and whats different from 25398. mostly made 1996 and on.

7. 25544, marked "dx2-66v16bgc/bgi". the newest 0.35mm process with 16kb writeback cache, made from 1997 into 2000s. also marked as: dx4-100v16bgc/bgi, dx5-133v16bgc. some are even marked as sv8b ones but still have 16kb cache.