Used my 66" cross bars and old Yakima Viper bike trays. I believe the Yakima fit guide says to use the small "claws" for the install, but I had an issue of the rail grab sliding up our sloped stock rack with the small claw, which grabs in the slot of the rail.
Was going to sell my Yakima Bedrock kit (for Tacoma bed), but was delighted to remember it came with SKS lock cores, which I was able to pull out and use on the rail grab assemblies.
I ended up using the medium claws, which grabbed the bottom of the stock rails and kept the assembly from sliding up, allowing greater contact. Overall feels like a solid install. I can move the truck quite a bit pulling on the crossbars without moving the rail grab assembly.
Megawarrior basket planned.
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