I installed a 670 box some years ago. I have those headers our vendors say are made for tri 5 chevies. They are stainless steel. We installed everything and the idle arm when you turn extreme left hits the header. I have tried to use a 6 cly idle arm and it does not clear. I have our factory set up with dropped link under the pan. I thought about shaving some off the edge of the idle arm is this a good idea?