The Fleece Performance replacement thermostat housing with auxiliary port is a direct replacement part for model years 1998.5 2007 RAM with 5.9L Cummins and 2013 2018 RAM with 6.7L Cummins. The auxiliary port is threaded to accept a 10AN 7 8 in 14 fitting to allow you to customize your coolant routings and includes port plug FPE SP 7814. APPLICATION NOTES Direct replacement for thermostat elbow included in our coolant bypass kits FPE CLNTBYPS CUMM 0712 and FPE CLNTBYPS CUMM 1318. Direct replacement for Cummins part numbers 5283433 and 3943297. Auxiliary port is threaded to accept a 10AN 7 8 in 14 fitting.