ZJ vs XJ Steering

Is there any difference between the Power Steering gear box used on the XJ as opposed to the box used on the ZJ? I only ask because I pulled one from a ZJ in the boneyard to replace the one in my XJ, but now it turns out I don't really need to replace it. I know they are interchangeable, but is there any advantage to replaceing the XJ box with a ZJ box? Someone has told me the ZJ box was improved but others have said there is no difference. The ZJ box came out of the boneyard and the door was missing, so I don't know what year it was or what the mileage was. It did look in fairly good condition though (except for it being wrecked on the passenger side).

I notice a def. improvement in steering... its much "tighter" with the redesigned spoolvalve. I dont know however if the improvement is worth changing the box out for. If you got a leaky box a ZJ box is the better deal but just to change it out I honestly dont know if i would do it

Thanks man, I think I will leave the old one in there for now. I only paid about $20.00 for the ZJ box, so I think I may keep it as a spare.

Now if I could just find a picture of the position the two hoses were in to begin with. It's been to weeks since I pulled them of of the box and I cant remember how they were routed coming off the box.

here is a photo i just took:



this is the zj box in an 88 xj btw

You truly Kick Ass!!!!!!!!!!!!!!!!!!!!!!!!!
Thanks a million for ALL of your help!