RideTech offers these Delrin Control Arm Bushings for 55-57 Chevy Car, OEM rubber control arm bushings allow too much deflection on the control arms. Poly bushings resist smooth rotation and impose stiction. Delrin bushings eliminate the deflection and the stiction, leading to a huge improvement in both ride quality and handling. Include bushings, inner sleeves and outer sleeves for front upper and lower arms. Direct replacement for factory rubber control arm bushings..