Stud kit fits all Littlefield, Blower Shop, Mooneyham, BDS and standard GM superchargers. It will not fit PSI, SSI or Kobelco superchargers.
Threads are a 7/16-20 on the nut side of the stud and on the manifold side a 7/16-14. The unique feature of these studs are that they have an external hex that make installation a snap with a 5/16" wrench. The hard anodizing helps prevent galling and the alum. provides light weight while providing a safety factor in the event of a supercharger backfire saving your supercharger or manifold.
Measurements of the blower stud are coarse thread is .850", shoulder is .800", fine thread is 1.20" with a .275" installation hex.