Steering Box Mounting
I think you're right. Shortly after I got the car, it started "wandering" on the road. Got underneath and found the steering box mtg bolts all loose. Then I found that castle nut placed in backwards, like some handy spacer someone figured on using. Probably it was a chronic problem. If this has happened to anyone else, I'd like to hear about it.
Welding some gussets is a good idea, too.