You have factory optional or aftermarket or dealer Auxiliary Rear Springs (helper springs/overload springs). Don't know of any bushing source. If you are not hauling heavy loads, take them off, you may get a better ride. Although they are advertised to only bear on the suspension under heavy loads.

Last edited by bartamos; 12/17/2020 8:03 PM.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn