I used a single pintle-hook mount to slide into the receiver, and had an identical plate welded on the carrier. Each plate has four sets of holes to put bolts in, and this allows quite a bit of up/down adjustment of the toolbox. I figured there may be a time when I'll need to raise it up high for clearance.
There are pintle-hook mounts made that have even more up/down adjustment than the one I bought.
I can't post a picture of it directly right now, but there's a picture of it in my reply on
this topic.:):)