Steering wheel off center

[dieseldavem]

I just replaced my steering box with a rebuilt unit from Red Head. The steering wheel is now off center a few degrees to the left when traveling in a straight line. The pitman arm can't be the issue since it has 4 larger splines in addition to the fine splines which prevents misalignment. The steering box input shaft has a flat spot on one side which prevents misalignment when making up that coupling. The truck drives fine with no other issues with the steering. Where did I go wrong with the installation?

[Betaracer]

Just adjust the draglink.