On a 63-66 it is not that difficult. You can use any GM truck power steering box up to about 86. You will need to get a Rez kit to mount the box off the frame. The later trucks have a dimple in the frame for the box the Rez kit solves that and it is available most of parts dealers in the links here. If you have a six life gets a little more difficult finding brackets to mount the pump. If you have a v8, it's just a matter of finding brackets to line every thing up. Some of the later stuff is metric, there are work around.
Larry
