My £2k estimate was based on something top draw like Crawford headers which would give you the best possible gains and would work all the way through to a balls-out N/A build.
adamphillie; apologies for the slightly arsey reply, lol, the fact that you've got a stage 3 stillen does change things a bit. The important thing to get right is the match-up between your headers and cams. Just looking at the lift and duration of cams doesn't tell the whole story, so do a bit of research of people with similar set-ups and look at what works and what doesn't. For example the Crawford headers with a Tomei cam grind seems to be one of the best (and most expensive) options for letting the engine rev, but with the stillen I'm guessing a higher rev limit isn't really what you're after so have a look at pairings that improve the midrange instead. The information is out there
DB
great thanks for info ill have a good look and get as much info as can..... no probs about rply either prob should of gave full story too lol.