Solid Steel Motor Mounts-Long Fits Various 1968-1972 Small & Big Block Chevrolet Engines Mr GasketMr. Gasket Solid Steel Motor Mounts are recommended only for competition applications. This . 18 Inch inch thick, zinc dichromate plated solid mounts do not have the Flexing present in rubber or even polyurethane engine mounts. This prevents lateral engine movement or twisting in high horsepower and torque applications. Nor will steel mounts break as easily as stock rubber mounts can. Engine movement in applications like this can cause contact of