The flange is less then a 1/4 inch from the floorboard. The Dougs headers are very small. My primer tubes I bet are almost the size of you exhaust pipes. My headers are 2 1/4 with 4 1/2 collector.
The car was built to have 70’s style look, with rear tire size 390/45R15 but when I get over this 70’s stance. I will lower the car as much as I can. The trans pan will be the lowest part hanging down.
Correct the car does sit high enough that anything hanging down would not have no issues, but I can’t stand it not to look clean underneath. A little fab work goes a long way and looks great.