pitman arm and steering box are indexed, none of that will help, original poster will have to adjust the drag link.
If he installed the steering box one full revolution off on the input shaft, he is going to have to disconnect the steering wheel shaft and recenter the input shaft. Disconnecting the pitman isn't really absolutely necessary, but what you want to do is find the center of the steering box and not the stops at the knuckles.
I usually center the box before I ever put it in the vehicle. But in my opinion doing it step by step is likely prudent. Lock the steering wheel to the center, disconnect the input, disconnect the pitman and center the box. Reconnect the input, it may not exactly align with the input shaft notch, but will be close. Center the tires and see how far off the pitman is, it should be close. If it isn't. I'd look first at the top trac bar connection. A seriously worn top trac bar connection can cause the steering wheel to be a quarter of a turn off center.
If your trac bar is good and you take a test drive and the steering wheel isn't center, then it is time to mess with the drag link.
My steering is about one and three quarters revolutions, from center, to the right and left stop. Or around three and half revolutions stop to stop. The disconnected steering box, if I remember correctly (it has been awhile maybe ask Oldman) is around two and quarter to two and half revolutions from center until it runs out of worm gear. It is possible to have the gear box off a full revolution when installing it. Then instead of hitting the steering stops, you run out of worm gear (or sector shaft teeth) inside the steering box in one direction.
I'm by no means an expert so I've always done it by the book, first zero the steering box and then start hooking everything up. I've never had any real issues doing it this way.
Depending on the year, you may have to re center the clock spring also, if you turned the steering wheel any when the box was out.