I understand the general concept of unibody construction, especially in modern cars, but (pardon my ignorance) I don't get what it is that makes the Ford Unibody different than the previous years. Can someone please explain what the 61 f100, for example, had that the 60 f100 didn't have? Obviously they were different body styles, but what exactly was different in the construction of the cab and other body parts that made it a unibody? Sorry if this is a silly question, but I can't find a simple answer. I have searched the internet regarding unibody construction and have gotten plenty of broad based answers, but I can't seem to find anything specific, especially as it relates to the Ford F100.