Dual snorkel hood scoop for my duster !!!

Year? 71 72 flat bottom. 73 curved bottom.
Is that correct..? 71 Hood isn't flat.. I thought it would take the tapered bottom. 72 Demon takes the flat bottom.. That's just what I thought. Correct me if I'm wrong, because I have one of each I'll be selling and want to make sure of the applications.