The LS"X" engines respond super well to basic mods. You do a CAI, shorty headers, good cat back and a good computer tune on a dyno and you can get 400+ at the wheels with a LS2. Throw a cam, mild head work and long tubes into the mix too and you will see 460+ at the wheels. Plus they make tons of torque really low in the RPM band. My LT1 Z28 made peak torque, 300ish, at 2900 all the way to 4900. FYI, don't race a 6 speed F-body or GTO from a 45mph roll. Thats right about where it starts to make max torque in 2nd
Damn it I miss that torque, I spun the tires going into 6th in Z28 in the rain. Speedo said somewhere around 130-145 but i was only moving forward at around 45 MPH.