FYI some guy pulled a 10.9 in a stock z06 with stock tires...LP640 is a Murcielago. LP560 is the gallardo and that does the quarter in 11.4 according to wikipedia. The ZR1 is supposed to do the quarter in 11 flat.
http://forums.motortrend.com/70/6474298/the-general-forum/marylander-drives-stock-corvette-z06-to-10sec-1-4/index.html