Our Cummins B-Series lower water inlet solves a common problem with Cummins swaps: How to make the lower water connection with the proper size hose and location?
Unlike the OEM water inlet (part number 3941929), our Cummins B-Series lower water inlet is available in the common 1.5, 1.75, 2, and 2.375 inch lower radiator hose sizes. In addition, our Cummins B-Series has a 1/2″ Female NPT fitting to accommodate a 5/8″ or 3/4″ heater hose or coolant return line. This lower inlet has a horizontal outlet direction as well as a rear-facing female NPT fitting. This provides an easier lower radiator hose installation in many different vehicle chassis.
Made from laser cut 3/8″ steel, this part is surface-ground and pressure-tested prior to shipment to insure a leak-free install. It can be directly mounted to your 6BT or 4BT block with the OEM sealing O-Ring, or installed with our die-cut gasket.
In addition, this Cummins B-Series lower water inlet can be used along with the OEM Cummins Mid/High mount accessory mount (part numbers 3930822 or 3930888). This inlet can also be used on any of the B-Series Cummins engines, including the 6BT and 4BT.
You can purchase this inlet individually via this listing, OR you can purchase the inlet as part of our high mount kit (to see a more detailed review and installation of that kit, check out our youtube video). We also fabricate and sell water inlets without a return fitting here.