Dual Snorkel air cleaner help...

My dad did this for his '70 Newport convertible for the same reason as you. He took the original 2 barrel single snorkel and made a 4 barrel duel snorkel air cleaner. He cut the 2 barrel opening out and weld in a 4 barrel one. For the snorkel, believe it or not, was the same as a /6 air cleaner snorkel so he cut the snorkel out of that and welded it up to the air cleaner. He had another factory duel snorkel air cleaner that he borrowed to get the measurements from. It turned out great and you can't even tell the difference.