Tranny fluid

[Chris Jones <sarophes@yahoo.com>]

  Hello folks,
  Can anyone help me with tranmission fluid for my
1974 non-OD spitfire?   Haynes says to use 90 wt
Hypoid.  All I could find at my friendly neighborhood
Auto Zone was in a funny little bottle (not like the
other tranny fluid bottles) and was marked "Marine". 
It says it's for "inboard and outboard motors".   But
it is gear oil, Hypoid 90 weight.  Anyone know what
I'm talking about?
   Thanks,
   Chris