First time at track last night
Exhaust (headers) will definately do that for you along with the gears and a good 60' you will probably see 12.6-12.5 if you can get a 60' in the 1.7 area. But who knows some LS1's are faster than others.
13.7 isn't that bad for stock in the summer.
Summer air to winter-time air should shave about 3-5 tenths off your time. Gears and/or convertor will wake up the car and give you the 12's you're looking for.
Derek


