Ok, I've got an interesting problem with the '66. Everytime I come to a stop sign, red light, or if I turn the wheels left, there is a loud thumping, the car shakes, and once in a while, it will stall. I know my exhaust head pipe hits the steering center link sometimes, but could it be the cause of this? Or could it be a broken transmission mount? I know my motor mounts are good, I replaced them both less than a year ago. Like I said above, it does it when I'm stoped, and the only time it does it when I'm driving is if I turn left. For now, it's a 200 Six with a C4 automatic. Thanks guys, Michael.