Question for the folks a lot smarter than I am! I am looking at a boat that has CAT C7 engines in it (2002 searay 400 Sedan bridge) I called ring power (cat dealer) and they sent me the service information and also a service schedule. It says that the aftercooler core should be replaced every 6 years. I have looked around and can’t find any detail on what is involved in doing this or relative costs. Does anyone have any experience with this or thoughts on the necessity of performing this? I should say the engines have 780 hours on them, have had the 250 hour service performed and oil and filters every year. Any help would be appreciated. Thank you!