dr's, stall converter, 3.73's , and you will hit high 12's possibly. Awesome man, I want to do an LS1 swap but not to sure about the gas mileage since gas prices are so damn high.
12's is pushing it witout a cam. maybe in a scsb with a huge converter and great traction in perfect weather. i dont doubt its possible. my full bolt on ls1 stock cam went 13.26 with a sluggy 1.83 60' time.
old mod list: H/C/I/N/E/G 408
new mod list: 5.3, gears/posi, mufler and tune : (