Flat Bottom Cowl Induction air cleaner differences

[John Brown]

I only have the last black 350 air cleaner bottom in hand to measure. I put a straight edge across the bottom and oriented it from front to back with the base turned upside down. At the front notch area (where it locks to the carb) it measures 1 13/16, and at the rear it measures 1 11/16. Someone else may have others to measure, but I sold the other 350 and the 427.