So I'm not fully clear on what exactly to even look for.
Well, first, practically speaking the pitman arm can only really be installed one way as it's indexed in four places. What you're looking for is contact between the pitman arm and drag link end and the sway bar when the wheels are turned hard left. You'll likely see a rub spot on the pitman arm, possibly a torn drag link end boot, and contact on the drag link end. You also may feel it bind the steering when on the trail.
I mentioned in another thread that after I replaced the steering box on mine and the rig still had the issue. Turns out the sway bar can shift to the right, which causes the problem. I noticed last year the the sway bar was hitting the frame cross member on both sides. I used an angle grinder and removed some material from both ends of the cross member. This, of course, made the pitman arm contact problem worse. A suggestion to use a hose clamp as a "stop" to prevent the bar from shifting too far to the right looks to have solved the problem.
To see if you have the issue, with the vehicle in park / neutral and the parking brake fully engaged, wheels on the ground and the engine running, have someone turn the steering wheel hard left all the way. Look at the pitman arm from underneath and see if there's contact with the sway bar.
My JK's steering never reaches the knuckle stop on the left side. Misses by over 1/4". Not sure if this is the case on other rigs or unique to mine. As suggested above, "re-indexing" the intermediate shaft is a thought, but when I tried it it limited full right, so it essentially just transferred the problem from side to side. I may have gone too far with the reindexing, possibly may try just moving it one spline and see what happens.