I think I have the Addco 150 up front, and I know the 675 out back. The front really stiffened the ride up, but I might have a slanted view because I installed it right after rebuilding the front suspension and disk brake swap. I used Mopar Performance SS springs out back so the ride in the back is already stiff. I never really noticed any heavy roll, just wanted to shore it up a bit. Honestly, even before the rear bar, this thing rode nicer than the wife's Yukon....lol