Performance is awesome, it was apparent right away that it made power over the stock mani and TB when combined with the Q45.
In the thread i made i explained the couple issues with installing it. The long bolt thats on the far right-side of the motor near the Throttle cable plate needs to be ground down a bit to clear under the plenum. Its a very tight fit between the firewall to get it in. Other than that there is a lip on the inside where the velocity stacks were welded to the stock runners. Nothing some time and a dremmel couldnt take care of.
Again i spent $400 shipped on mine and i would say it was worth it by far. It did take some working over. Oh and you can only use the far left and far right fuel rail bolts as the plenum is too close to the others. Dont know why he even put the bungs there for the back bolts. But no issues with it at all and it looks great on there. Havent dynod the gains yet and maybe never will but we will see. As far as butt dyno goes i can honestly say it definetly had significant gains and when your already at 460whp it takes significant gains to really be able to tell them apart. 19psi feels like it was when at 24psi, Thats the gain im talking about.