I've have two different 70/71 Dusters with both sixpak and Hemi SS scoops on them on race weight hoods. Both needed multiple(3 or 4) hood pins or Dzuz fasteners on both the front and rear edges of the lift off hoods, my old pump gas Duster had the hood attached to the stock hinges and still needed four Dzuz fasterners in front of the scoop off of the radiator support and two behind the scoop between the stock hinges to keep it halfway close to staying flat at or above 125 MPH in the 1/4 mile. I had to add another set of Dzuz fasteners on the side of the hood between the front set of fasteners and the hood hinges also to keep it flat along the sides
Be safe, do it right once to start with