Steering road sway

[Rg500gamma]

At the start of my dad's 72 c/k 20 resto I had road sway or wandering with the steering and the excessive movement needed in the wheel to keep it on the straight and narrow was a *****. I have 33s on it and wondering if other components are needed to bring it back to instant compliance. I had went to the steering box and to remove any play in it. I am putting a new rag coupler on the steering shaft
The ball joints are still the originals and they are going to the trash.
Anyone run into this by just installing bigger tires ?
Or am I going with a fresh steering box as well
Thanks all