www.ClassRacerInfo.com It will show you all the specs and do the classification calculations for you so you know what classes and the race weight in each class. Plus, you will see the engine specs, replacement heads and their port volumes, all the accepted parts - pistons, rods, oil pans, blocks, cranks, etc. - listed on one page. You won't have to chase all over the internet to find what you need. There is even a link to flow figures for some of the heads.
http://www.classracerinfo.com/CGPage...&MAKE=Corvette
http://www.classracerinfo.com/EngineSelection.aspx