The 8800GT superclocked and 8800GT non-superclocked are physically the same card.  The difference between the cards is that the 8800GT superclocked has been tested and verified to run at the overclocked speeds advertised and will run at the overclocked speeds by default.  While it is possible to obtain the same clock speeds with the non-overclocked edition of the card it is not guaranteed to produce the same results.