Those clamps are useless against turbo backpressure I tried it. Use ball flange or v band. I had the best luck with ball flange as they are more forgiving.

11.67@118 1.88 60' with only 7-8 lbs of boost. Turbocharged, megasquirted, 407 BB, 440 source heads, roller cam, 9:1 comp. http://s292.photobucket.com/albums/mm14/beansgracie