OK Zzark. First center the front wheels so they point straight ahead now disconnect the steering box from the steering linkage. Then turn the wheel fully one way. Now count the revolutions it takes to go back completely the other way, turn the wheel back half that amount and you will have the steering box centered. Now have a look at the differance between the pitman arm on the steering box and the ball joint on the steering linkage. If they do not line up you may be able to adjust the linkage to make up the differance. Or you may have a bent steering linkage. If your front sheet metal lines up ie the hood fenders and grille. I would say your frame is not bent all that bad. Check to see if it is square, get a friend and have them help you cross measure the frame from identical points on each side. Shiming the box slightly is probably ok. but not what I would call a safe fix. Give it a go let me know how you made out. i'm sure with the wealth of info on this site there is not much that can't be figured out.