Found this link online that says the HP jump could be up to 50%. It is a 7psi boost. Not 7hp boost.
http://superchargersonline.com/produ...=PD-K10525-201
Found two or three other sites selling this kit for roughly $2500 shipped new. Not too bad but way outta my range for a Blazer anyway. Would rather buy a used 3rd gen Camaro and play with that instead.