at one of my other forums, a guy has a blown C5 Z06...and one of his friends got a new Z06, and it has already been on the dyno to prove those hp numbers to be low...

it has also been shown that the LS7 responds very well to simple mods...the one simple mods setup ive seen was header-back exhaust, a TB, and a tune, and it was up over 600hp.