Need help identifying early A-body auto trans

Not all have the PK in front of the #. Not sure why but that's the way it is. 2538386 doesn't show up in my list but all the torqueflite's made in 66 start out with the 253 designation. I have never seen a 727 behind a /6 in an a-body so I believe it must be a 904 and I'd bet it's a 66 model by the #