Description Sherwood GC1‑01 is a raw water (seawater) engine cooling pump with 1½” inlet and outlet ports, designed as the original‑specified replacement for early Cummins 6B Series 250 HP engines; accepts Sherwood 15000K impeller and major repair kit 23981. A core return fee may apply. Please call us on 1300 202 272 to find out more.