I've got a 98' 7.4L and it takes a
AC PF-454 oil filter (easy number to remember) and 5.5 or 6.0 quarts. I
only run MerCruiser 25w40 stern drive oil. I have started running the synthetic blend version of their 25w40 stern drive oil. Everyone has an opinion on oil brands but I have a friend that ran automotive oil and it caused the low oil pressure alarm to sound at idle. I say stick with the manufacturer on this one and run their oil.
