There are two main approaches to mounting cargo cases to our rack system:
Select a case long enough to span the distance between the two cross-frames.
Enjoy a broader range of options when you mount to the "Carrier Deck".
When properly installed the cross-frames are 50" apart from each other, measured center to center on the top surface where the mounting holes are. To comfortably mount a cargo case directly to the cross-frames you would be looking for one that is at least 55" long.
Many of the popular cargo cases do not come in this length. We have identified two cases from different companies that should work as long as you do not overload them. Check out Condition 1 's model 2106 and Nanuk's model 995. For mounting methods search online for how to videos. Spoiler alert, many will have you drill trough your case to pass fasteners though to the rack. Not the most sophisticated way to do it which brings us to our second option.
Bring in the "Carrier Deck" - With this addition to the rack system you greatly expand what can easily be attached and transport.