7.3L Ford Powerstroke Motor
This port in the side of the water pump housing it plugged with a 5/16" square drive 3/8"NPT plug. Simply remove the plug and install a 3/8"NPT to 1/8"NPT adapter and screw in the sender. On this 2000 Ford 7.3L Powerstroke we are installing the water temp sender in a "T".  This is due to the customer's installation of an aftermarket coolant filter requiring a hose connection.