I just installed 454 into my chevy dually, it has bored 60 over with 9:1 flat top pistons a Lunati cam with semi rough idle.The transmission is a stock turbo 400. The problem I am having is in traffic I have to ride the brakes because it wants to keep pulling when stopped. right know the idle rpm is set at 900. I feel that I need to get a different torque converter but not sure which way to go with it or do I need to lower the idle some more. This is my first go around with using automatic transmissions so I can use some advice.