Could any of the VW racers on the forum please provide information on where I could locate a top quality water pump with a METAL IMPELLER? Should any other modifications be made to the pump such as removing impellers, using a larger/smaller pump pulley, (will be Gilmer). Any other suggestions concerning improvement of cooling system such as placing a restrictor in the thermostat housing, plugging, increasing/decreasing / water passages in the block or head? New to VW engines and seeking information on the water cooled VW. Appreciate any comments and thanks for your time and consideration on this topic. Thanks, Jerry Poole (JerryPoole@Arkansas.net