i will second that LE packages are sweet, i have the mods in my sig and with only a base tune and street tires i went 12.1 at 120 mph in a full weight t-top camaro with 18" z06 wheels when i went to the track. i would do 383 it will make the car much more streetable because you will have a lot broader torque curve. I have about 7-8k in mine but i did a lot of the work myself.

Scott