On my Allante, I noticed that the transaxle has "junkyard writing" on it.

The Allante came with an F7 transaxle, which is essentially a beefed 440t4. The 440t4 was later renamed the 4t60.

How can I tell which one of the three I have? Rebuild kits are different for the 440t4 and 4t60, so there must be some internal differences. Are there external codes that identify the transaxle somewhere on the case?

Usually there is a tag or casting marks that will tell you what you have. I did some looking around on the 'net but couldn't come up with any info. Maybe someone else will chime in with something.

When I had my car on the ramps to do an oil change, right on the bottom of the tranny, evgraved in it, it said 4T60-E

maybe it does with yours?

There's a large tag riveted on the back, but as is common, the paint flaked off long ago so the info is gone. There are some stamped letters, but they don't correspond to the info in my service manual, which would make sense if it was a later model trans.

The guys on the Allante board seem to think that, even though the mechanicals are nearly identical, the internal electrics on the F7 are different than the 440t4, so its likely its a newer F7.

I am rebuilding it (same kit for either) and it looks internally just like the book says it should.