At the bottom of the link, the writer suggest the new LS7 in the new vette is the same as the engine in the Z/28. No news there but he also suggests that the new LS7 approaches 600hp. Could it be that they are testing with an older LS7 but will offer the newer one in the Z/28??
http://www.autoevolution.com/news/20...014-62780.html