oldschoolhdmike wrote:
pretty sure my holes are not slotted....
In most cases, the hole is clearly larger than the bolt diameter. So, yes, the bolt can shift, even when tight, due to the forces involved. However, usually both sides will move by the same amount. Looking at the pics, it doesn't appear that bolt placement has shifted on either side as there is no evidence of exposed, unpainted steel around the washers.
The other possibility is that there are broken welds on the bracket that holds the pin box, check the curb (i.e. passenger side). If the welds are ok, then check to see if a cross member is bent. Check both the main one in front of the brackets and the rear one. This won't be ez as you probably have to drop the skin.