It is not hard at all to make that kind of power on a 6 speed LS3. With a cam and supporting mods they are 470-480 rwhp on average and I have seen some big cams on good fuel break 500 rwhp.
I still expected the powerband, DCT, and the weight advantage of the M to wipe the floor with the Camaro though. Even the owner of the Camaro said he didn't expect to win:
http://ls1tech.com/forums/street-rac...r-torq-hd.html