Would changing the motherboard change the region?

I know there is a question regarding motherboard swap, but it does not address my exact issue.

I am seriously considering swapping the motherboard in my white 3ds (japanese model) with a USA motherboard, either a broken 3ds or a new motherboard. Overall makes not a huge difference to me.

I would want to know if doing something like this would change the region on the system from NTSC-J to NTSC (from japanese region to united states) which is the entire point of the project.

However before committing myself to such a project I would want to know if it would have the results I would intend, and if there would be any conflict with parts.

Would the cart reader for the 3ds need to swapped as well or would just the motherboard be sufficient?

I do not know if anyone has tampered with such a project but any information would be helpful.

And I do know its a large amount of in order to change just the color, but to be honest I abhor the colors available in the USA. And with no white 3ds available for the USA, and no replacement shell housing in my desired color this is the only alternative.

Thank you in advance.