The T1 bar increases the total rear roll resistance by 20% over the Z51 part.
In this picture, you can see how much bigger the T1 bar is over the Z51 bar. The Z51 bar is bigger than the base model bar as well.
The T1 bar is a direct, perfect fitting replacement to the stock bar.
New center bushings are required. The OEM and T1 bushings are lined with a Teflon cloth anti-squeak and anti-stiction layer. The T1 bushings are also harder. Cool stuff!
The rear bar in place, showing the aluminum collars that prevent lateral shifting of the bar.
The stock end links are stiff cast aluminum that have noncompliant ball joints; no unwanted flex there!
Now the front bar is removed. Once unbolted it can be threaded out of the car without dropping the subframe, unlike many late model cars. Having a lift makes this much easier because you can get angles that might be hard on jackstands!
The front T1 bar is larger in diameter and accounts for an overall 40% increase in front roll stiffness.