The EGR on mine created a huge flat spot around 2000-2700 (I removed it months before the manifold project). I plan on reinstalling it with some minor modifications but just have not made it around to doing so. When I put the manifold on it was a single upgrade deal. A few days later I installed a Jacobs Ignition system. Like the article said the manifold showed gains in all the unexpected areas (1800-3200 rpm). It could be that the manifold made gains up top as well and those where only apparent with the new ignition. I must say I was pretty darn happy with the truck but after my recent purchase and transition to "The Dark Side" I gotta say the 3.0 sucks. If Toyota would just put a motor like I have in my recently acquired 02 Maxima then I would be one happy camper. For what its worth I have never actually driven a stock 3.0 so I'm not a real good judge on performance increase. I just know on my already modified motor the manifold was totally worth it.