Looks to me like they work like normal traction bars but on normal traction bars if you preload the rubber against the spring it can give you a stiff ride.With these traction bars if you remove the rear bolt like the guy says the bar will simply pivot up and down with the leaf spring(theres another bolt up by where the U-bolts connect the bars to the rear end.If you put the bolt back in at the rear of the bar it makes it a one piece bar again.At least thats how it looks to me Looks like a good idea and I would assume the front of the bar is clamped to the spring
I had a set of these on a 70 Mustang back in the late 70's. They worked pretty good for a bolt on traction bar. Very similar in operation to any traction bar except for the rear bolt. If the price is right, and this is what you are looking for, they would accomplish the same results as a new traction bar setup.
96 Ford F350 PSD CC DRW
64 Fairlaine 500 rust bucket/future Tbolt clone with 501 BBF