Cognito Motorsports SM Series LDG Traction Bar Kit, 0-5.5in Rear Lift (SKU 110-90459)

Bars that run from the frame to the rear axle to stop axle wrap. Axle wrap is when hard throttle twists the rear axle against the leaf springs, which you feel as a hop or a bang under load. Cognito builds these from boxed sheet metal and makes them adjustable after they are bolted on so you can dial in the pinion angle.

why this one — Only worth buying if you actually have the problem, which on a Duramax usually means a tuned truck, big tires, or heavy towing off the line. Cognito's version is adjustable after install and does not restrict suspension travel the way a cheap bolt-on bar can, but at roughly $1,750 it is the most expensive part on this list by a wide margin. A stock-power truck with factory tires will not notice the difference.