To retorque or not to retorque? That is the question.

I have never bothered to retorque after the motor has fired. But I do normally torque 90/100ft in 3 steps, then allow it to sit over night to give the gasket time to compress and seat. Then the next day I will go back through the sequence and loosen and retorque one at a time. I always torque the upper bolts 10lbs more to counter the intake wedging and pulling up. Never had a problem, and I run 10lbs of boost on one of my cars.