HI There.. a Roush stage 2 has the stripes and the body parts plus the suspension upgrades but not the Roush charger or engine upgrades.
So yes it should be the same horsepower as a stock GT. If you had 412 then you where looking at a 2011 specs. I know that Roush is putting a super charger on the stage 3 put I am not sure if they are ready to order yet.
Drakesnake