Crank center line in '66 Cuda help needed

Before you put the 727 tranny in there, take a good sized hammer and peen the mating line of the firewall and floor pans (pinch weld I believe) towards the front or rear of the vehicle - I've had best luck flattening it forwards. If you don't do this, the bell of the tranny will hit the protruding metal of the pinch weld. If I remember correctly, it needs to be flattened for about 10" on either side of center.