I have finally acquired a few pieces of Nn3 and Z rolling stock especially for testing and demonstrating various small power trucks I have been developing. What first appears is a great similarity in size and I'm aware that some of the trucks are the same as well as couplings and coupling height standards. This has led to the question, are some of the Z pieces the same as the Nn3 pieces? Or are some of the Z pieces usable as cores that with minor tweeks can be converted to Nn3? One in particular would be tank cars. Also, the physical size, at least, of box cars. The reason I ask is I don't have examples of each to compare. I acquired several Z tank cars but none in Nn3 to compare. And I have several Nn3 box cars but none in Z. They sure look to be very similar in scale size. Anyone with experience that could shed some light on this for my own general knowledge going forward?