My quickest time to date is a 13.80 with catback and a jet chip. If the weathers cold enough and your able to get up to the line with engine temps between 170 and 180 you'll get your quickest times. These pigs suffer allot from heat soak.
I know you asked for the 5.7, but i have ran my 6.1 over 100 times, and the best time so far is 13.08 @ 109. Thats w/Diablo and Airaid intake only. Box stock it ws need on 13.5 @ 104. pretty close each run.