We have them in our boat. Great engines. I replaced the stock raw water pumps with the SMX pumps this winter. I have an aftercooler on order since I looks like they were never serviced. I will replace one and use the old two to make a new one for the second engine. As said above Tony Athens is the Cummins guru and he loves them. Just service the aftercoolers on a regular basis. Tony has a video on how to do it properly. We have about 1,500 hours on ours but I wouldn’t be afraid of 4K hours.
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