I'm trying to modify an attachment to fit in place of my bucket. The idea is to mount some U-channel, like shown in the photos, to the new attachment, so it will accept the loader arm and cylinder ends. The U-channel is approx. 3"x3"x1/4" thick. All I can find online is U-channel with shorter sidewalls ... i.e. 3" wide but say 1-1/2" sidewalls. Am I calling it the wrong thing, or looking in the wrong places? Or is the only option to but square stock and cut one side off?