Steering Help Please

I have a 1968 Mustang Coupe with a 289. It has power steering. I just upgraded the steering box to a flaming river box, which works great, but there is still play in the control valve, which is brand new. Thats the only play in the system. How do i make this better. Thanks Please Help

Not too sure on the new box, but this is just what I did on my original. It may or may not help.....just giving advice. The control box for the steering should have a large nut with an upside down bolt in it. The bolt should have what looks like a notch cut in it for a screwdriver. You have to hold that bolt stationary while you break the nut loose and as you tighten the night it should tighten up the steering on your car. That should help you out. I hope it works. -crosses fingers-

1. Alignment Issue
2. Check the alignment/torque specifications of the shaft connecting to the top(?) of the steering box.