That is a great question!
I reached out to my contact at M-3 who makes the Locking Floor Mounted Storage Box for Enclosed Trailers - 19" x 29" x 7-1/4" # M387FR you were wanting to add to your cargo trailer, and the box is indeed rated for an ATV or UTV rolling over it when loading and unloading.
I included a video of the # M387FR for you to take a look at. view full answer...
The DeeZee Specialty Series ATV Toolbox # DZM207 is 35" long x 12" wide x 12-1/2" tall, and the height does not take the lid into account. The interior dimensions of the toolbox will be the same, minus roughly 1/8". If you let me know the year, make and model of your truck I may be able to find something that works for you. view full answer...