An aluminum water-pump housing is lighter than a stock cast piece, but in Stock Appearing racing, it needs to look completely stock. A few modifications are needed. (A) The temperature-sending unit hole is plugged because it is in a different location than those in vintage '70 units. (B) A hole is then drilled and tapped in a location replicating the stock '70 location for the temperature-sending unit. (C) The MP aluminum housing also has an extra boss for alternator mounting, which must be removed.