From our findings, it's definitely worthwhile to spend a little time investigating which headers will work best for you. The first step is to get on the phone with your header manufacturer's technical representatives and make use of their knowledge. Good header manufacturers spend a lot of time testing different header designs against just about any engine package you can think of, and their R&D experience can be invaluable. Also, if you really want to know for sure what works best for you, buy several. Headers aren't so expensive that most teams cannot afford to invest in a few sets for testing. Maybe you can even go in with a few other race teams (that all run Chevy's or Fords) and agree to buy and share several R&D sets so that all of you can test and see what works best for you.