Which Trans do I have F4W71A or B

[z3beemer]

So I've spent the last hour or so searching the forum trying to confirm which trans I have.  Every time I think I've got if figured out I find another post that seems to contradicts what I thought I confirmed.  I'm doing a conversion, auto to manual, on a 73. When I bought the car the 73 was complete and I got an engine and manual trans with it from a 72 Z.  I have no idea of the vin # from the 72 so I have no idea of the mfg date.  Looking on the manual trans  I can't find any legible numbers on the casings other than casting numbers.  Is there an easy way to tell from looking if it is  a F4W71 A or B? The shifter lever looks like the pic below.  Not sure if that helps but one of the post I read said you could tell from that.

[CanTechZ]

The type A is a three piece case design like this:

 

Type B is a two piece case design,

[jfa.series1]

Also, the type A shift lever is straight while the type B shift lever is bent per your picture.

[z3beemer]

I just love this site.  There is so much knowledge here, and everyone is so helpful.  Thanks again to all of you!

z3beemer (Paul)