Surface isn't level?

[tRiGgEr]

I don't think I understand what you are asking...

Would you not just put the box down on the surface...

[tRiGgEr]

Indeed. But if you put the box on a not level surface, your box then will become unlevel.

It's not a bucket of acid. It's fine as long as it is secure. If you think about it driving down a hill will level it

[Silver]

How big in your truck is that surface?

[ruckus]

If you want a tight fit then built it thats shape then lay a flat piece over the top of the basicly making it a double bottom. flat for the inside of the box and curved to hug the floor. problem solved.