Over the winter I installed my new 408LS engine along with Spohn K-Member, A-Arms, and coil over kit. My car is mostly drag race with some street driving so I don't have a front sway bar and I have a manual S-10 steering box. I had the car aligned after the installation of all the new parts.

At about 45-50 mph I get some side to side motion in the steering wheel. Its not a vibration, the steering wheel just wants to move side to side. Its more pronounced on a rough road or one that is more crooked or crowned. It does it some on a smoother road but its not as noticable. The side to side steering wheel action goes away at faster and slower speeds. I took it up over 100mph yesterday and it was completely smooth.

I've double checked the torque of all the suspension components, nothing seems to have any excessive play in it. The streering box has just a little play in it but I'm not sure how much is normal. The steering box is rebuilt from autozone so its probably what I would suspect. Anyone have any other ideas of what it could be?