If you're like me and had to put an Edelbrock or aftermarket Carter AFB series 4 barrel (5-1/8" inlet) on your original classic because the original Carter WCFB or Rochester 4 barrel just never ran right.  This is for you.  Very quality heavy Teflon material machined out of stock to fit the top of the new carburetor and then allow the original factory 4 barrel (4-7/32") air cleaner to fit.  There's a bunch of the cheap adapters that go the other way to put an aftermarket air cleaner on the stock old carburetors but couldn't find any to do this way.  Notice the smooth radius edges to not restrict any flow.  Made to sit on the Edelbrock and Carter AFB carburetors but will not fit a Holley because of all the choke housing in the way. It does increase the air cleaner height 1" so you guys with low hood clearance, this can be an issues.