Originally Posted by Old Chuck

The grand sport is what was the Z51 option with some Z06 goodies thrown in. It now has a dry sump and the LS3 is hand built with all the dry sump engines. The engine still is listed as 420 hp. however, it beats the old Z51 by two tenths in 0-60 so most feel that it is putting out better then 420 (or 436 with the optional NPP exhaust). Any car that can do 3.9-4.0 is serious. It will however, not feel as good as the 370 when going around sharp corners. Chevy produces a Corvette Grand Sport every decade or so.