Williams boxcars are scale length, but they aren’t accurate scale models. They are too narrow and a little too short to match any prototype based on the details.
Essentially, the molds were made for the 3-rail market for hobbyists who demanded more realistic-looking models than the 6464 cars.
But unless you’re running a strictly traditional railroad or strictly a scale railroad, it shouldn’t really matter. The cars fit in well for most layouts.
