Heat exchangers may be installed in either tank for the purpose of cooling automatic transmission fluid or engine oil. Heat exchangers are the most effective when installed in the down stream side of the radiator. Whichever tank they are installed in requires a minimum width of 2". The exchanger inlet and outlet are installed with your choice of 1/2" NPT, 1/4" NPT, #12 A.N. or #10 A.N.. Center to center distance on the inlet and outlet is 10-1/4" or 12-1/2".