Cross Over Steering Question

[71biggreenk10]

I have read alot of posts talking about cross over steering, and one common thing that I have found is the need for a 2wd steering gear box. Can anyone tell me why it is necessary for the 2wd steering box? The reason I ask is because I recently purchased an AGR Superbox 2 4wd model. From what I have read, there are supposed to be 4 ways to mount a pitman arm on the AGR box, but I haven't been able to get a solid answer on that. I'd prefer to not have to buy another steering box, as this one is awesome, and isn't cheap, and is practically brand new. Thank you for your help.