I think if the hole in the hood does not match the base of the scoop you are not getting the full potentional of the scoop. But before you cut a bigger hole wait to see what some of the others like Mr_P_Body have to say. I have found that it takes more than you would think. Also I would think with the hole in the hood being smaller it would cause a turbulence more than forcing or having a fresh air effect for the carb. to pull air. On my R/T it work best with the hole & air pan cut to match the scoop. It worked so much better that on my dragster I built a pan not only to raise the scoop but to have more volume.