This is a great subject, that came up at a good time, as I have been thinking about fans on my Factory Appearing build. I have a big block A body and standard its equipped with a 7 blade fixed fan with a 5/8" spacer , hoping that one of these short clutches fits and put the fan in a good spot within the shroud, otherwise a fixed 4 blade fan might be finding a home in it for racing.
Been doing a lot of reading up on these clutches and the fans as well John. Right now, I'm leaning toward the 2947 clutch with a 7 blade fan unless someone convinces me that a different combo would be better. As I mentioned, I'm more concerned with cooling efficiency rather than hp loss.
