Per Chevy performance, we have 425. (engine? wheel?) looks to be engine. car probably has a super stout bottom end that is waiting for huge power upgrades. and the weight, OMG.
EDIT, after looking at what is inside that 427 copo engine, and at the fact that it spins to 8000rpm, that thing is making HUGE power. 600? 700? on a 3200lbs chassis. Holy geez. why do they give the Z28 the 505 hp (7 year old Z06 engine design) when they can bump power up that high in an LS7.