[Healeys] identify transmission

[sdesalvo at frontiernet.net]

Hi all,
I have a late BN1 which sometimes has BN2 parts. I am trying to identify the transmission, the manual is not helping because it refers to the number stamped just below the dipstick. There is no dipstick, just a filler plug on the right side of the tranny. Can anyone tell me how to identify the BN1 tranny vs the BN2? Thanks in advance for any help.
Sam