PRO/STOCK air cleaner research ??

When I was a kid in the early sixties I commonly heard them called 3/4 inch cams. Good old Midwest living. Still very funny to me.
The 3/4 cam was a real thing. It started with the Flathead Fords. There was a street cam and a race cam and Ed Winfield decided there was a need for something in between and the 3/4 cam was born. MANY camshaft vendors had a "3/4" cam for various applications even listed in their catalogs for many years.