Davey - if your steering column is any indication of the front end it might be from a 73-87 truck. I had and 81 Suburban and you could drive it with one finger. But your steering column and wheel, in your pics, is from a 73-87, and I bet that means a few suspension parts are as well. As for the uneven steering I do not know. Not to scare you but I had a Fqrd that did not steer even from right to left and I eventually learned that the frame was broken at the front crossmember, which was the reason it had been "unalignable" to that point. I am sure that is not the case with your truck.
I would start by looking at the steering linkage and seeing if everything looks right. If the front end is pieced together as you describe there could be a few parts that are not working right or just plain wrong. Good luck.
