[Lizard King]

I think the variance in speed is caused by the factory engines being really different one from each other. Some produce monster power out of the box others are just normal.

At the track here most of the LS1s run bests of 13.5... I have seen one run a 13.19 with exaust done, and this weekend one ran 12.99 with exaust and street (DOT approved) slicks.

There main issue is launching. The torque band is very strong at low RPMs, so either you get wheel spin on start or as soon as you ease into it. Most of them run 2.2-2.3 - 60ft times. Putting a set a slicks on them is a gamble as well since their rear end is not toughest.