As for the boxes I would a say no as they have handles and aren't quite the right size. Check out what others have done by looking at packs that have passed. For the caps the ribs do look cool but you have the threads showing so that would be hard to deal with. I used a coupling and sanded down to the built in stop and made a interior plug so it looked like a TD cap, sorta. Check out my EIB for photos. Fumantroops pack is right up there too. Good luck!