Not positive on the clutch fans, but I believe it would be the difference in how they opperate or function. I know newer versions are actually wired as opposed to the older coil spring etc...

The baffels are between the bumper and the core support at each side to prevent air from going around the core support. They are a rubber flexable piece that clips to the support and to the lower valance with special clips...

A few of the repro places carry them now...

Hope you get more specific answers on your clutch fan question...

Brett - 67 Drop Top 455!