Technical Air Cleaner Identification??? 66 or 67 Chevelle?

Got this air cleaner laying around the shop and it looks like the mid to late 60's Chevelle and Camaro air cleaners with the horn on it, but when you flip it over on the bottom, there is two vacuum / air lines rather than just one, or one on the horn like the old Camaro's. Anyone have any idea on what this was for?

Here's some pics...









Any good info will get a 'like'!!!

Thank you!!!

 

I'm thinking bigger truck.....

 

low hp big block quadrajet, snorkel points to the left(drivers side)