Well.. acording to some of the latest info it is said that GM fixed the head issues for the 2012 year. Time will tell.
Also.. a ls7 in a c6 puts down around 440rwhp. This car is still not sae rated and in a different chassis with a different drivetrain. The number could go up or down however 440rwhp is what I would expect.
With a 3820lbs car (-300lbs. than a zl1) she should perform close to a zl1 in a straight line but according to the marketing the z28 is 3 seconds faster on the track. A second is almost an eternity... 3 seconds is just bananas!!!!! No ford pony car can touch that... not even the 700hp (real hp) gt500.