hmmm... well i think stock LS dynos at around 110 or 115 and if was a hot day then you have lost a couple of hp from that. What elevation are you runnin at? 16.5 is a little slow in my mind, stock LS runs 16 flat. I have AEM CAI, DC header, DC exhaust, and gears, and my best run at the track is 15.2 with full tank 17's and two 12's in the back............I also live in charleston SC where its 15 feet above sea level so............