March's Ford 429-460 Serpentine Drive Pulley Kit components are CNC-machined from solid billet 6061-T6 aluminum to fit perfectly and handle high torque and vibration. Complete with stainless steel tensioning rods and chrome moly rod ends for high-performance operation. Matching pulleys are powdercoated clear, and they will not fracture like common cast pulleys. Their high tensile strength means much longer use. March goes as far as hard coating each pulley's high-wear areas. The street rod ratio increases water flow and fan speed to improve critical, low-speed driving.