Yes, they work to prevent wheel hop. Do they make your tires get better traction? A resounding NO. They should really be called wheel hop bars, but that would sound too goofy *LOL*.
If you always do what you've always done,
You'll always get what you've always got http://www.classic-mustang.net/johnpro
http://www.classic-mustang.net/john66/mustang/pics/66fsides2.jpg<P ID="edit"><FONT SIZE=-1>Edited by johnpro on 03/31/01 00:26 AM (server time).</FONT></P>
The Caltracs type that feed force back into the leaf spring...or the torque link type that soften the hit to the tires might help a bit but the underride/override Shelby type, as Johnpro states, just fight axle wrap under acceleration and braking. Which is a better traction situation than the axle a bouncin and twistin without control.
Go with the Traction-master (Shelby type), they will keep it more "original" and they eliminate wheel-hop - mine made a huge difference even when I had my piss-poor shot engine.
These have to be welded to the frame, there are others that bump the frame that are easier to install, I like the look of the traction-masters too.
69 Sportsroof, 351C, 4spd toploader, Restomod BOSS 429 clone - the one and only (?) 1969 BOSS 351