Just so you don't waste time wondering what the heck is going on (like I did, until I called Borgeson). I begin rough alignments by making the pitman arm angle parallel to the frame rail when the steering box is adjusted to be on center. But, the Borgeson unit bolts in at a 4.5 degree angle, so when the Borgeson box is on center, your pitman arm won't be parallel to the frame rail, resulting in the tie rod lengths being unequal when both wheels point straight ahead. Borgeson had to put in the 4.5 degrees to adapt their GM box to the Mopar K-member mounts. You can see that 4.5 degrees on their site, on their installation drawing. The Borgeson engineer I talked to said their box has to be on center when going straight ahead, and that it is not OK to fudge it off center to make the tie rods equal length. He didn't say what the reason was, so maybe it's for straight ahead tracking stability, or maybe so the turn radius isn't changed, or maybe for "return to center" force after the turn, or maybe something else. I don't know. But, I would rather have equal length tie rods, so if anyone out there thinks it is OK to start with the steering box off center, please let me know why.
I'm running pump pressure on the low side because I like the feel better, and sometimes I swear I can feel the difference in force (caused by the 4.5 degree angle) between starting to turn left or right, when starting from straight. But, it's barely noticeable, and probably not noticeable at the recommended pump pressure.