im a little late adding to this post but i just got my 03 cobra back from the shop and had similar results. i had the whole billet flow pulley kit added(2.76), a bassani x-pipe with high flow cats, cold air, thermostat(160), and tune. we got 450hp and 487 torque. pretty impressive considering i still have the side exhaust on the car. still toying with changing back to a cat back bassani also.