Thank you, thought it maybe around 6100mm. Understand about the detailed info. Enjoy your build process.Hi. The overall length of the box is 6800mm and the interior measurement is 6084mm. Yes, I have detailed drawings with measurements but they are proprietary and I'm not allowed to share those. I'm sure if you contacted SLRV and asked for information on the Acela 6x6 box, they'd be happy to give you a more detailed layout of the interior. Good luck in your own build. As much as I want this NOW, I've actually enjoyed the planning and build very much as well.