Anybody know where this goes?

[texas04]

So my Blazer has been in the body/paint shop for the last couple of months (should be out sometime between Christmas and New Years), and when I went by the shop yesterday to check out the progress they showed me this part (see pics below) that they could not find a place for. They went ahead and sanded, prepped, and painted it but are not sure where to put it. The part is about 4 ft long, is bent into a channel, has holes pre-drilled for fasteners, and has a slight bow in it. For the life of me I cannot figure out where this thing goes, so I figured I would take it to the forum for some input from guys with a lot more experience than myself. Any thoughts on what this is/where it goes?

Thanks