If you would have left your exhaust stock you probably would have 36 lbs. of boost. Boost is basically the resistance of air flow. The more air you flow out, the less boost you are going to have. On my truck, i was making 37 lbs. with the stock exhaust. I then installed a ATS manifold, 16 cm turbo housing, and a 4 in. exhaust. My boost dropped all the way to 31. But i had more power and less smoke. So boost isn't everything sometimes.