I had a Hemi hoodscoop in my street car and had the same issue.
I found aluminum tubing, polished it in my drill press, and cut it to 4 sections.
Each section of tube was secured by 4 long stainless screws and locknuts, from the topside of the scoop and the nuts on the inner hood side.
It wasn't the prettiest, bit it definently kept the scoop from wanting to (or at least looking like it was) blow off.
?