Stefano, these guys just made 505 rwhp with 1 7/8" primary longtube headers, cam, modified factory exhaust,cold air intake, 25% underdrive pulleys, 160* thermostat, plugs and wires.
http://www.ls1tech.com/forums/2010-camar...aspirtated.html
The base was the 350 rwhp run, followed by their "stage 2" cam which was 460 rwhp and the last was the "stage 3" cam coming in at 505 rwhp.