Where your turbo outlets meet on the intake pipe, they need to be as far from the carb as possible. If you don't, the motor will have issues with proper fuel/air distribution between the cylinders. In other words you could possibly have a lean condition on one bank, and rich on the other.
I saw this issue first hand on a procharged mustang on the dyno. He had the intake pipe slightly off to one side, and it caused nothing but problems. Just trying to save you the headache he went through trying to figure out what was going on.