Carb gasket 69, 340?
I always had issues with the factory air cleaner and hood clearance if I tried to run anything much over 1/4 to 5/16 in thickness. That hood on my Dart is so dang close. Always had to run the factory size thickness on the air cleaner just be sure nothing was touching. Used a drop down air cleaner for a while to get a little more flow but I liked the factory look of the stock air cleaner. I'm weird I know.