My car is up on jack stands at the moment so I can't measure ground clearance to the header flange, but as mentioned in my post above, my flange only sticks down about 3/4"-1" below the frame rail. It's tucked up there pretty well. I will measure my ground clearance once the car is back on its rubber, but that is a function of ride height. I was wondering how your flange relates to your frame rail. That's a fixed dimension that is not affected by ride height.