Dual snorkel hood scoop for my duster !!!

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.
70, 71 demon and dart hoods are smooth centre. Believe 72 also. In 73 and up, rib runs down the centre of the hood.