The ones on my 52 2ton grain box dump look homemade. There's a dangling bolt off the bed and a slotted bracket for it to slide into on the frame. A short rod welded to a nut lets me tighten the bolt to the bracket.
It is necessary to use this I found out when I started piling stuff on the rear of the bed and the bed started to tip. The rear of the bed is 3ft past the pivot point.
Dan


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