From what I can tell, the 2010 and later engines have access to change the fuel filter from above - a cap is removed and the filter can be plucked out. Filters on earlier 6. 7's are a bit of a bear to change in my opinion. You have to get at them from the side and underneath. So I wondered if the earlier engines could be retrofitted with the necessary parts (mounting, filter holder, tubing, fittings, water sensor wiring etc) from a later model to improve the situation. It might be too expensive, and maybe there isn't space in the earlier engines, I just don't know. Someone with knowledge of both engines may know.