Dyno runs show 391 before and 404 after installing manifold but the guy says 61 HP gain how tf did that happen?

http://www.americanmuscle.com/boss-i...1gt.html#lcdiv

 

Don't believe everything you read.

 

Yeah that's a bit of a misleading video, the 61 hp gain is "above 7000 rpm" and they don't give a lot of details on the baseline tune used. The gains are pretty flat to that point. But the whole point of the Boss manifold is top end. When the stock IM efficiency drops off at 7k, the Boss manifold flows well enough to keep making power well past that. In my research many are using tunes that take the redline with the Boss intake to ~7700 rpm. Unless you spend a lot of time up there though (IE road racing), you're probably better served with the stock manifold and a good tune that defeats the torque management down low.

 

Stock IM actually drops off at 6500.