what radius is minimun for my engine?

[jojoesbigboy54]

i want to purchase an o gauge williams J class 4-8-4..need to know if item # 40399 requires o-42 or larger?
cataloge on line does not say,but has measurements..22 inches..please help so we can by the right trackage..

[glennk28]

you might find beter results on the "Williams" list down a couple of lines.  gj