Steering box problem
 

I've got a problem and hope somebody can help. I just finished changing my streering box on my 83 GSL with one from an 85 SE. While the car is off the ground, everything turns fine. After I put it on the ground, turning to the left is fine, when I turn right, it binds up just past center to the point of not turning. I can turn it back left a little and then back to the right and it will go on, but very tight. Is this box also shot or is there something else? Everything in the front suspension was changed with new stuff, except the strut tops.
Any help is appreciated. Otherwise, it's off to find another box.