Rick, funny you should ask that.

I never got the speed nuts right for my repro scoops, then slowly ganked them up over the years by cross-threading the studs. I finally ended up using large black rubber grommets and a bit of silicone to hold them down under the hood.

No vibrations for sure using this method. My scoops have always been OPEN for the air and I've never had any issues with this technique.