Available in either aluminum or cast iron Holley Action Plus water pumps feature a heavy duty shaft, with a 5/8in pilot. Their premium quality bearing and seal have twice the load capacity of stock pumps. Weiand's exclusive housing counter bore keeps the bearing from Walking-Out. Each pump is Triple-Tested for leak free operation. Action Plus pumps come with Weiand's exclusive 6-blade stamped steel anti-cavitation impeller which uses less horsepower to pump more water. All pumps are designed with the necessary bracket bosses and water connections to fit popular street applications. Weiand's high-performance Action-Plus water pumps are a MUST for today's hotter running engines.