Bruce-those rail covers actually have an internal expanding clamp to attach them down in the stake pockets on the stepside type truck. On my S-10, they simply clamped on the inside of the top bed rail.
They (Extang) call them the "No Damage To Truck" tonneau-and they ain't kidding! The price isn't too bad, either. Dunno if they've got a website or not, might be worth a Google.
Regards,
Wannabe
