This billet thermostat adaptor allows you to use custom water lines on your 4.0L barra engine and inserts into the same spot as the factory hard line pipe on the thermostat housing. It has an AN10 male thread and utilizes the factory o-ring and retaining clip. This is also needed for clearance when fitting our forward facing intake plenum.

This billet thermostat adaptor allows you to use custom water lines on your 4.0L barra engine and inserts into the same spot as the factory hard line pipe on the thermostat housing. It has an AN10 male thread and utilizes the factory o-ring and retaining clip. This is also needed for clearance when fitting our forward facing intake plenum.