63-66 idler arm conversion to late model thru bolt ?

Kern Dog said
Wide tires and aggressive cornering will result in more stress to the area. This will also result in steering deflection and reduced steering precision.
140 in a straight line on a smooth drag strip is great but it does not stress the steering like cornering does.

I am not a drag racer. My cars handle, always have. Alignment spot on for years and many miles. They probably changed because it was cheaper. We tend to over analyze everything, when most of what Ma Mopar did was way overkill. Never fix what is not broke.