The 458 GT2 comes with a 4.5 liter V8 with 470 PS (346 kW) and weighs in at 1245 kg. That is 100 PS less than the 458 Italia's standard configuration.
(http://imgs.blackfalconmedia.com/2010/12/9/medium/1834985412328285633.jpg)
Ferrari 458 GT2 racer testing at Fiorano (http://feeds.worldcarfans.com/~r/worldcarfans/Jxfz/~3/vOSbGW8Bsgs/ferrari-458-gt2-racer-testing-at-fiorano)