Not sure about Auto Zone part numbers. I'm sure they will be able to tell you with the Pollak number.
I didn't get the trans with the motor so I stayed with 700r4 208 and 3.73s.
I used the stock manifolds, the driver's side kind of point in to the frame. Just have to have a bend in the pipe connecting to it to bring it back out.
Here is some more on getting a factory style AC compressor to work.
http://67-72chevytrucks.com/vboard/s...d.php?t=510656