Hard to tell, I haven't dynoed the car after every mod. It's a carry over from the old days. The intake on the Xfire looked cleaner than they used to look, so I suspect that the gain was minimal. The flow numbers showed only a small gain and that was near max so it might give a little at the top end. I think where a lot of false info comes from quotes of gains for individual mods, ie. 40-45 for DCAI then 15-20 for modded manifolds but combine the two and you won't get 65, there the gain is closer to the lowest total, ie. 55 or less. Just like when I was young, you find a lot of stretching the truth when it comes to cars, even on this forum.That's why most of the seniors say show us the slip or dyno sheet, it's also why I keep my numbers to myself, I'm not trying to prove anything to anybody. I just enjoy tinkering to see what I can achieve. Be happy with whatever you get.