I just replaced the Sherwood raw water pump on my Universal m3-20 with a Oberdorfer n202m-16. I was afraid I would have to modify it as explained on other forums. I'm pleased to say it was a direct fit. Only had to slightly modify one hose fitting end. I ordered the pump from Cardinal pump. $220 w/free shipping. I recommend the up grade. The Sherwood G903 is a pain to service and expensive. The part about almost having "Miss Izzy" sink is a subject for another forum.