2005: The biggest change in 2005 was the replacement of the LS1 engine with the LS2 engine. The new 6.0-liter unit produced 400 horsepower and 400 lb-ft of torque, making the GTO a beast with a 0-60 ...

It's fitting that during the 50th anniversary year of the small-block Chevy, arguably its two greatest variations have been released. First, the 400hp 6.0L LS2 arrived for the '05 model year in the ...