I have a set of Super Comp on a 440 71 Challenger. The passenger side hangs down at the collector about 3 inches from the floor pan. The driver side fits nice and snug. There is no way you could lower the car without draggin one side. What does companies like just supension, PST recommend because there is no way this header would work with lowering the car. I put a set of 17" rims on the front with a 40/245 tire. I know it's lower than typical but not that much. And the header on the passenger side scrapes any speed bump. Have to be real careful, but the drivers side is not a problem. Any suggestions on which brands fit snugger to the bottom of the car.