I was talking to squirrel nuts on the phone last night and what he suggested was, if you have the money, estimated 1k give or take 200 after installs, get an LT4 Hot Cam kit and get SLP LOUDMOUTH exhaust. The exhuast is 350 and the cam kit i think is about 450. Not only will you gain about 25hp and 30lb/ft of torque, so you will FLYYYY, but it is obnoxiously loud as you wanted. Here's a clip of a T/A with this done to it
http://www.exhaustsoundclips.com/sou...4_hotcam2.html