With those mods on a 03/04 cobra you may break 500hp at the flywheel, but not at the rear wheels. You might get anywhere between 420-460rwhp, depending on which parts you use.
I have the Diablo chip, 2.93 pulley, MAC cold air induction, BBK throttle bodies and full exhaust(headers, x-pipes, no cats, cat-backs) and I am getting 440rwhp. I plan on getting the Apten ported blower, 2.80 pulley with 100mm idler and should get 500rwhp with a good tune.