I went with the Edelbrock 650 AVS II. To make the base fit the carb I rolled a piece of .040 alum. 2 1/8" long and notched the top to fit the bumps in the base, then put hi temp sealant to attach it. Backyard mech. style, cheap and it works.
Reluctantly, I recently put a 4 barrel Holley on top of my 68 Fury III’s 383. The throat has a 5 3/8” opening. I really don’t like aftermarket air cleaners so I’ve been thinking...Would there be a period correct factory air cleaner that would properly fit on top? If so, I’d like to find/buy one on eBay. Thanks...