Can I mail my 1040X and form 843 together?

I need to amend my federal return, and I also need to file a form 843. It seems that they each should go to a different IRS mailing address, so I was not sure if they need to mailed separately to their respective addresses or if I can I submit both of these by mail in the same envelope? If so, I would probably send it to the address for the 1040X? Thanks!