If the PCB P/Ns of the devices match then the hardware is 'the same' but you may have other problems with a conversion, it's not guaranteed that it'll happen smoothly just because of matching PCB P/N and flashing US/EU devices to an Asian fw can be problematic because of incompatible voice/text/etc. files which then have to be replaced with correct ones.

Conversely, if the PCB P/N of the two devices and their respective firmwares are different then a conversion is not possible.

Read this thread to understand more about conversions: [Only registered and activated users can see links. ]. Post #7 tells how to find the PCB P/N in firmware and to see it on the device you open hidden menu behind the battery symbol (hold symbol for 5-6 seconds to reach the menu) then press lower right corner/"Back" or "Next" repeatedly until you see a page headed "Version Information nuvi ...........". The PCB is shown in the top line.