I know this has been answered before but I can't find it. I understand that the basic difference between a car and truck engine is the cam. What is the difference and which is better for mileage with an AOD and 3.55 diff. I currently have a car 5.0 in my 90F150, is it worth the bother to change the cam? I also have a low mileage 351W that I am cinsidering swapping in but have no idea what cam is in it. It is an F0AE block. I do very little towing.