It doesnt show it on the Chevy website cause its very limited to only a few states but soon be available in 05, as with the VHO it stands for Vortec High output using the Vortec 6000 LQ9, horsepower stays the same at 345 but the torque increase a little, its not AWD compared to the SS but a decent performer and rival against the Hemi or should i say Magnum Dodge.