A light bulb popped on in my head when I read your reply! Making the oval openings slightly larger could serve 3 purposes. 1- It would alleviate having to repair or replace the metal in the opening where you remove the existing snorkel. Simply make it just big enough to use existing metal to roll an inward lip. Replicate it on the passenger side of the air cleaner, and done! 2- It would really be unnoticeable at a casual glance, but would be pretty obvious to someone requiring an original 70-71 340 air cleaner. 3- Better air flow for a 408/416 disguised as a 340 in a stock looing car! :)