Brain fart...trying to install new studs on dual scoops

Alright, I'm not sure why it's not working, but the self tapping studs arent tapping, they're just eating the channels that they're supposed to sit in. I have two scoops for my 70 Dart hood and was missing 8 studs between the two scoops. I got a bag of extra studs and need to toss them in, but hit a hiccup. Can anyone recommend a way to get the studs to thread into the underside of the scoops? I got a couple nuts on the fine threaded portion and push down as hard as I can while threading them in, but they won't thread very deep at all.
Would a Helicoil work?