The biggest thing is to get the PS pump bracket. I got the stuff for mine from an 82. I was told that is when they went to O rings so leaks are less. I also got used but if you can get the pump bracket I would probably just buy all new so I don't have to worry about it. Really easy swap.
You will need a Pitman arm for PS. You will also need to change the Spline thing at the end of the stearing shaft. It is a little bigger on the PS pump. I Also installed a MOOR Stearing bracked to get rid of the movement from the old 2 Piece. This did cause some problems. I had to mount to the bracket then to the frame because I could not get to all of the bolts. Works Great and Turns really well. If you want more detail PM me.