i have done 12.70 @ 109 a year ago on the stock clutch. it was slipping on the 5000 rpm takeoff and the 1.92 60', and slipping every shift till the end. i am still on the stock clutch as of now, but i am going to be putting in the ls7 clutch settup for now. and saveing for the twin disc settup later as my modding gets much deeper!!!!