1989-2018 Cummins Engine Block Heaters
1994-2018: These replacement engine block heaters are threaded directly into the engine block.
1989-1998: This replacement engine block heater is installed directly into the freeze plug and requires gasket part number 3910517.
Note: Before ordering your replacement block heater, check and see which engine block heater your truck is equipped with. There is some overlap of years between 1994-1998.