you really should read the discussions on this over at Camaros.net
many of us have been going through this and there are alot of variables.
the new Hooker SuperComps are not what they used to be and the fit sucks.... especially if you have power steering.
in many cases, the designs look identical, until you try putting them on your car.
the headers that are known to work well are Dynatech, and Dougs, - Stahls are superb but about 3x the price (if you include ceramic coating)
the reproduction Z28 headers are also fine, but even more expensive than the Stahl versions.