Manual Steering questions
I would take the pitman arm off the power box if you can. Yea otherwise take both boxes in. Then get the whole manual box. You want the splines to fit the manual box but the arm to have the right ball joint on it which points the correct direction (up VS down)
So, anyways. All you need is a small spline (manual) pitman arm which is compatible with 73 up steering linkage. :) The 73 up steering linkage is superior in my opinion. Someone else will hopefully chime in with a proper PN.
Far as I know there is not a large spline manual pitman arm / large spline manual box.
Since you have a number of cars, you can compare the pitman arms for a 71 VS a 73. I am pretty sure that the 73 UP has the ball knuckle that points down.
Heck, nevermind, here is a thread that explains it all.
http://www.forabodiesonly.com/mopar/showthread.php?t=62906