I am trying to find a rack system for a 2000 Silverado Step-side. The bed itself is square, no lip or channel on the edge to clamp over. The best option I have been able to find is bolting clamps to the inside of the bed so I can lay a rack on top of the bed rails. Not having channels on the inside of the bed is limiting my options, anyone have a good solution? Or suggestions for clamps? There is a tonneau cover mounted using bolted-on clamps, I'm just not sure where the former owner got them. Trying to find information on the step-side is a bit of a trick.

I do have an adjustable rack that I can shorten down to the ~49" wide bed, if I can find clamps or an alternative.

No channels to clamp to

Flat clamp, bolted on and holding the tonneau