A pulley change is all you need. Putting your stock headers back on will move u in the wrong direction power-wise. U just need to crank the boost up a little. Also, peak hp is probably coming in closer to 7000rpm. Have u been driving it? How's it feel?
Feels smooth power delivery wise, but I was told the procharger come with a 4.38 pulley and mine came with a 4.0, shouldn't I be making more boost that just 5psi? I thought with stock pulley I was supposed to be at 7psi