Should I get the Martin 345 or 640 case for my DCX1E?

I recently bought a Martin DCX1E after my old guitar recently imploded on itself. I want to protect the guitar the best i can. I know the 345 is heavier but I have only seen that advertised as being specifically for the DCX1E and wanted to know if it would be safe to buy a 640 as it is a sturdy lighter case. So basically all i'm wondering is, will my DCX1E be able to fit as well in a 640 as a 345 or is it designed specifically for a different line of Martins? I am not looking for a "somewhat sure" answer, I want a straightforward and reputable confirmation. Thank you