With a Torque converter it'll be a good idea to get a trans cooler as well.
The PI heads and Cams will totally wake up your car and still look stock under the hood
Supposed to give you more power, less drone inside the car, louder outside. Think they were a bit bigger as well...
http://www.flowmastermufflers.com/cgi-bin/flowmaster/super40.html
It was a production vehicle that Shelby built. Every now and then they pop up on ebay. They used Vortec Supercharged 4.0L Aurora V8 Engine, or the N/A version
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2453648652&category=6465...