steering box

[76bonanza]

Here is my problem my truck pulls to the right, not alignment, not rims or tires. Seems to be the steering gear box. if I lift the front end and start the truck the wheel will move to the right a little.SOOOOOO Someone told me the box may not be centered. Does this sound right? The box was a reman bought about two years ago I did not own truck then so dont know any more about it. So my question is if it is not center right how do I check it or recenter it? (I know nothing about steering boxes so simplified step by step would be nice) Or is this just not what could be wrong?