i was told by Terry Schaffer at power parts engineering that he came up with the design and SB followed, if its true i dont know but it is what he told me. it wasnt any brain surgery to do it. and there were no patent's, 3 companies were already dong it, It's a 13" borg and beck devoloped by GM in the 70's pressure plate (off the shelf item) customized by the builder (adding heavier springs) with a floater plate and a couple of disc's. and maybe a few more thing's, however we use only the best materials available, and we do not get them from china, they are for the most part made in the USA.