Seen stock blocks hold that.... too many questions I see here instead of facts... People dont need spend too much time calling here there and everywhere... Just don't detenate it and run a sportsman unless you plan on making well more than 800hp.. Thas all you need to know. Otherwise your doing yourself no justice.. and if someone tells you a stock block won't hold over 500 hp then don't ask that person for advice again.. if someone tells you a sportsman won't hold more than 600 don't ask that person for advice either...