MERCRUISER : 496 MAG (H.O. Model) Model Serial Ranges 0M025000 THRU 0M687143 0M687144 THRU 0W059999 0W060000 THRU 0W309999 0W310000 THRU 0W649999 0W650000 THRU 1A066165 1A066166 THRU 1A350678 1A350679 & Up